Smithsonian Channel

Investigate one of Egypt's oldest monuments to eternity: the Buried Pyramid of Sekhemkhet; explore a well-preserved underground tomb and view a mysterious sarcophagus during the first-ever on-camera exploration of this 4,500-year-old sacred place.

Part 6/6. Unearth the dramatic final days of the Twentieth Dynasty's great warrior king, Ramses III; view a rare judicial papyrus that recounts the story of an assassination plot hatched in the royal harem; see what the monarch's mummy reveals today.

Visiting Australia's One Central Park, the Oslo Opera House and the California Academy of Sciences in San Francisco to reveal their architectural secrets.

Investigate one of Egypt's oldest monuments to eternity: the Buried Pyramid of Sekhemkhet; explore a well-preserved underground tomb and view a mysterious sarcophagus during the first-ever on-camera exploration of this 4,500-year-old sacred place.

Part 6/6. Unearth the dramatic final days of the Twentieth Dynasty's great warrior king, Ramses III; view a rare judicial papyrus that recounts the story of an assassination plot hatched in the royal harem; see what the monarch's mummy reveals today.

Deploy futuristic lidar technology to map the Amber Road, an ancient trade network linking the Baltic Sea to the Mediterranean. Follow researchers as they retrace the route and reshape our understanding of historical trade and cultural exchange.

Learning how displaced artifacts spark fresh investigations and rewrite timelines; unearthing a forgotten tragedy in a remote mountain lake in India, checking out footprints that change human migration stories; reopening an ancient cold case.

Revisit the crimes of Jack the Ripper as investigators try to ID his first victim; chase the Mad Gasser, who terrorized an Illinois town in 1944, then hunt for the Servant Girl Annihilator, a killer who stalked Austin, Texas, in the darkness.

Deploy futuristic lidar technology to map the Amber Road, an ancient trade network linking the Baltic Sea to the Mediterranean. Follow researchers as they retrace the route and reshape our understanding of historical trade and cultural exchange.

Learning how displaced artifacts spark fresh investigations and rewrite timelines; unearthing a forgotten tragedy in a remote mountain lake in India, checking out footprints that change human migration stories; reopening an ancient cold case.

Revisit the crimes of Jack the Ripper as investigators try to ID his first victim; chase the Mad Gasser, who terrorized an Illinois town in 1944, then hunt for the Servant Girl Annihilator, a killer who stalked Austin, Texas, in the darkness.

Deploy futuristic lidar technology to map the Amber Road, an ancient trade network linking the Baltic Sea to the Mediterranean. Follow researchers as they retrace the route and reshape our understanding of historical trade and cultural exchange.

Traipsing along ancient pathways crisscrossing Easter Island; finding gigantic designs carved into Asia's Eastern Steppe; ascending a tall pyramid rising from Antarctica's icy landscape.

Crews work around the clock to build the world's largest underwater concrete bed to salvage the Costa Concordia; operating in secrecy, teams work under high security to repair one of the world's most iconic cruise liners.

Tackling the grade 6 rapids and untamed waters of the Buller River on the west coast of New Zealand's South Island, blessed by a Māori elder of the Ngāti Apa ki te Rā Tō.

The St. Lawrence River is one that forged North America, allowing ships to traverse the continent; the adventure begins in Canada's first capital city of Kingston and near Canada's second-largest city of Montreal.

Exploring some of the most cavernous places on the planet, including an expansive Siberian crater with no explainable origin, Greenland's bizarre black holes, an ancient forbidden well in the Yemeni desert, and a voluminous void in Antarctica.

Salvaging a 50-foot motor yacht in Islamorada, Fla.; a 44-foot launch hung up on a dam on the Mississippi River; repairing a major storm gate in the British Isles.

The St. Lawrence River is one that forged North America, allowing ships to traverse the continent; the adventure begins in Canada's first capital city of Kingston and near Canada's second-largest city of Montreal.

Exploring some of the most cavernous places on the planet, including an expansive Siberian crater with no explainable origin, Greenland's bizarre black holes, an ancient forbidden well in the Yemeni desert, and a voluminous void in Antarctica.

Salvaging a 50-foot motor yacht in Islamorada, Fla.; a 44-foot launch hung up on a dam on the Mississippi River; repairing a major storm gate in the British Isles.

Uncovering the design and engineering secrets behind the Grand Canyon Skywalk, the Audain Museum and more.

Mike Davidson goes on a cross-country road trip to help the Well Done Foundation; they work to find and cap some of the estimated 2 million leaking, toxic abandoned oil and gas wells scattered throughout the U.S.

Deploy futuristic lidar technology to map the Amber Road, an ancient trade network linking the Baltic Sea to the Mediterranean. Follow researchers as they retrace the route and reshape our understanding of historical trade and cultural exchange.

Learning how displaced artifacts spark fresh investigations and rewrite timelines; unearthing a forgotten tragedy in a remote mountain lake in India, checking out footprints that change human migration stories; reopening an ancient cold case.

Revisit the crimes of Jack the Ripper as investigators try to ID his first victim; chase the Mad Gasser, who terrorized an Illinois town in 1944, then hunt for the Servant Girl Annihilator, a killer who stalked Austin, Texas, in the darkness.

Deploy futuristic lidar technology to map the Amber Road, an ancient trade network linking the Baltic Sea to the Mediterranean. Follow researchers as they retrace the route and reshape our understanding of historical trade and cultural exchange.

Learning how displaced artifacts spark fresh investigations and rewrite timelines; unearthing a forgotten tragedy in a remote mountain lake in India, checking out footprints that change human migration stories; reopening an ancient cold case.

Revisit the crimes of Jack the Ripper as investigators try to ID his first victim; chase the Mad Gasser, who terrorized an Illinois town in 1944, then hunt for the Servant Girl Annihilator, a killer who stalked Austin, Texas, in the darkness.

Germany's selection of strange bedfellows in the form of despots and dictators comes back to haunt them.

The overlooked underdog of British fighter planes; fast and versatile, the dogfighter doubled as a bomber and ground support aircraft in every theatre of WWII.

Join intense manhunts for the world's most wanted terrorists and outlaws. Investigate the covert raid on Osama bin Laden's compound, trace the tragic trap set for a dissident journalist, and track a notorious arms dealer nabbed in a huge DEA sting.

Germany's selection of strange bedfellows in the form of despots and dictators comes back to haunt them.

The overlooked underdog of British fighter planes; fast and versatile, the dogfighter doubled as a bomber and ground support aircraft in every theatre of WWII.

Join intense manhunts for the world's most wanted terrorists and outlaws. Investigate the covert raid on Osama bin Laden's compound, trace the tragic trap set for a dissident journalist, and track a notorious arms dealer nabbed in a huge DEA sting.

Germany's selection of strange bedfellows in the form of despots and dictators comes back to haunt them.

Exploring some of the most cavernous places on the planet, including an expansive Siberian crater with no explainable origin, Greenland's bizarre black holes, an ancient forbidden well in the Yemeni desert, and a voluminous void in Antarctica.

Salvaging a 50-foot motor yacht in Islamorada, Fla.; a 44-foot launch hung up on a dam on the Mississippi River; repairing a major storm gate in the British Isles.

The St. Lawrence River is one that forged North America, allowing ships to traverse the continent; the adventure begins in Canada's first capital city of Kingston and near Canada's second-largest city of Montreal.

Navigating the historic Potomac River from West Virginia to Chesapeake Bay, passing through Washington, D.C. and the national monuments and ending at George Washington's Mount Vernon estate.

A perfect circle carved around an ancient peak; a scary phenomenon in the Pacific; strange shapes in a Middle Eastern desert; a formation below the ocean's surface.

Jeremy Birch takes on a salvage to raise a vessel with a concrete hull; it's been in the Fraser River for a month, collecting silt and mud, adding 30 tons to its deadweight.

Navigating the historic Potomac River from West Virginia to Chesapeake Bay, passing through Washington, D.C. and the national monuments and ending at George Washington's Mount Vernon estate.

A perfect circle carved around an ancient peak; a scary phenomenon in the Pacific; strange shapes in a Middle Eastern desert; a formation below the ocean's surface.

Using computer simulations, it is possible to fly over other worlds and see how galaxies interact.

Paid programming.

Examining the chilling precision of three high-profile assassinations, uncovering the technology behind a bladed missile, investigating a deadly car bomb in the American capital and reviewing CCTV footage of a nerve agent attack in a crowded airport.

Reliving the daring 17-minute hostage rescue at the Iranian Embassy in London that was caught on live TV; learning how US teams ran deniable missions in Southeast Asia, then seeing the global threat of a Russian nuclear cruise missile with limitless range.

Witnessing the fierce urban combat of the Battle of Mogadishu after a quick mission spirals out of control; exploring the fallout from a downed Cold War spy plane; cheering on the commandos who crippled the Nazi atomic program in a daring raid.

Examining the chilling precision of three high-profile assassinations, uncovering the technology behind a bladed missile, investigating a deadly car bomb in the American capital and reviewing CCTV footage of a nerve agent attack in a crowded airport.

Reliving the daring 17-minute hostage rescue at the Iranian Embassy in London that was caught on live TV; learning how US teams ran deniable missions in Southeast Asia, then seeing the global threat of a Russian nuclear cruise missile with limitless range.

Witnessing the fierce urban combat of the Battle of Mogadishu after a quick mission spirals out of control; exploring the fallout from a downed Cold War spy plane; cheering on the commandos who crippled the Nazi atomic program in a daring raid.

The overlooked underdog of British fighter planes; fast and versatile, the dogfighter doubled as a bomber and ground support aircraft in every theatre of WWII.

Join intense manhunts for the world's most wanted terrorists and outlaws. Investigate the covert raid on Osama bin Laden's compound, trace the tragic trap set for a dissident journalist, and track a notorious arms dealer nabbed in a huge DEA sting.

Relive the Flight of the Crow, a trek across Nazi-occupied Europe; find out how two Austrian mountaineers hiked their way out of the Himalayas, then learn why 378 Japanese POWs risked it all in Australia's bloody Cowra Breakout.

Five months after D-Day, the ground war finally arrives on German soil as British soldiers attack in the shadow of Hitler's infamous Siegfried Line.

While Nazi Germany attempts to cover up the brutal murders of a serial killer, a brilliant detective uses early forensic methods to bring him to justice.

Relive the Flight of the Crow, a trek across Nazi-occupied Europe; find out how two Austrian mountaineers hiked their way out of the Himalayas, then learn why 378 Japanese POWs risked it all in Australia's bloody Cowra Breakout.

Five months after D-Day, the ground war finally arrives on German soil as British soldiers attack in the shadow of Hitler's infamous Siegfried Line.

While Nazi Germany attempts to cover up the brutal murders of a serial killer, a brilliant detective uses early forensic methods to bring him to justice.

Relive the Flight of the Crow, a trek across Nazi-occupied Europe; find out how two Austrian mountaineers hiked their way out of the Himalayas, then learn why 378 Japanese POWs risked it all in Australia's bloody Cowra Breakout.

A perfect circle carved around an ancient peak; a scary phenomenon in the Pacific; strange shapes in a Middle Eastern desert; a formation below the ocean's surface.

Jeremy Birch takes on a salvage to raise a vessel with a concrete hull; it's been in the Fraser River for a month, collecting silt and mud, adding 30 tons to its deadweight.

Navigating the historic Potomac River from West Virginia to Chesapeake Bay, passing through Washington, D.C. and the national monuments and ending at George Washington's Mount Vernon estate.

A journey down one of the wild rivers in the world, the Yukon; the unusual trip starts in an aircraft piloted by a painter and the odyssey ends with a visit to a graveyard of disintegrating rear-wheel steamers.

Decoding the secrets of long-lost human settlements; scrutinizing a mysterious Norwegian mound, a prehistoric stone circle on the banks of the Tagus River, a lost city in the cradle of civilization and bizarre rock shapes.

Chris Ward sets out with Josh Moreira and Ward's younger brother to salvage a light aircraft that's sitting on the seabed; Jeremy Birch braves the arctic conditions to salvage two vessels that have fallen prey to the crushing ice conditions.

A journey down one of the wild rivers in the world, the Yukon; the unusual trip starts in an aircraft piloted by a painter and the odyssey ends with a visit to a graveyard of disintegrating rear-wheel steamers.

Decoding the secrets of long-lost human settlements; scrutinizing a mysterious Norwegian mound, a prehistoric stone circle on the banks of the Tagus River, a lost city in the cradle of civilization and bizarre rock shapes.

The second-largest planet is also a mini-solar system with 60 moons and those crazy rings.

Paid programming.

Exploring behind-the-scenes of design and construction of revolutionary buildings in Spain, New York and a university campus in Florida.

Host Mike Davidson goes to the remote Atacama Desert in Chile; at observatory ALMA he works alongside the expert team as they repair some of the world's biggest antennas.

Relive the Flight of the Crow, a trek across Nazi-occupied Europe; find out how two Austrian mountaineers hiked their way out of the Himalayas, then learn why 378 Japanese POWs risked it all in Australia's bloody Cowra Breakout.

Five months after D-Day, the ground war finally arrives on German soil as British soldiers attack in the shadow of Hitler's infamous Siegfried Line.

While Nazi Germany attempts to cover up the brutal murders of a serial killer, a brilliant detective uses early forensic methods to bring him to justice.

Relive the Flight of the Crow, a trek across Nazi-occupied Europe; find out how two Austrian mountaineers hiked their way out of the Himalayas, then learn why 378 Japanese POWs risked it all in Australia's bloody Cowra Breakout.

Five months after D-Day, the ground war finally arrives on German soil as British soldiers attack in the shadow of Hitler's infamous Siegfried Line.

While Nazi Germany attempts to cover up the brutal murders of a serial killer, a brilliant detective uses early forensic methods to bring him to justice.

Exploring the design and engineering stories behind D.C.'s Museum of African American History, the Montreal Tower and the Equinor building in Oslo.

In the Alps of Switzerland, Mike helps an elite team install a new cable (rope) system on an iconic mountain gondola line, helps fix the world's steepest cogwheel railway track and explores mountaintop family farms only accessible.

Going on a journey across Lithuania on big trains packed to the brim as massive ships wait to collect their bounty and take it across the ocean.

Exploring the design and engineering stories behind D.C.'s Museum of African American History, the Montreal Tower and the Equinor building in Oslo.

In the Alps of Switzerland, Mike helps an elite team install a new cable (rope) system on an iconic mountain gondola line, helps fix the world's steepest cogwheel railway track and explores mountaintop family farms only accessible.

Going on a journey across Lithuania on big trains packed to the brim as massive ships wait to collect their bounty and take it across the ocean.

Exploring the design and engineering stories behind D.C.'s Museum of African American History, the Montreal Tower and the Equinor building in Oslo.

Decoding the secrets of long-lost human settlements; scrutinizing a mysterious Norwegian mound, a prehistoric stone circle on the banks of the Tagus River, a lost city in the cradle of civilization and bizarre rock shapes.

Chris Ward sets out with Josh Moreira and Ward's younger brother to salvage a light aircraft that's sitting on the seabed; Jeremy Birch braves the arctic conditions to salvage two vessels that have fallen prey to the crushing ice conditions.

A journey down one of the wild rivers in the world, the Yukon; the unusual trip starts in an aircraft piloted by a painter and the odyssey ends with a visit to a graveyard of disintegrating rear-wheel steamers.

Meandering through the black waters of a primordial river immortalized in a folk song.

Zoom in on some otherworldly sights; spot a giant glacier on the Red Planet, let the milky seas off the coast of Java bathe your vision, ponder a huge hexagon floating above Saturn and take a spin around a doughnut-shaped lake in Saskatchewan.

Bundles of cedar wood tree trunks are smashed apart, releasing thousands of logs on the shoreline; Jeremy and his crew must work fast to recover the cargo.

Meandering through the black waters of a primordial river immortalized in a folk song.

Zoom in on some otherworldly sights; spot a giant glacier on the Red Planet, let the milky seas off the coast of Java bathe your vision, ponder a huge hexagon floating above Saturn and take a spin around a doughnut-shaped lake in Saskatchewan.

Bundles of cedar wood tree trunks are smashed apart, releasing thousands of logs on the shoreline; Jeremy and his crew must work fast to recover the cargo.

Navigating the narrow, deep fjords that lead to Narvik, Norway, where German and British forces faced off in April 1940; repeated torpedo failures threatened to sink the mission and leave Hitler's invading troops exposed and vulnerable.

Learning why a clash over Nazi ideology wrecked a bright U-boat commander's career.

Exploring the design and engineering stories behind D.C.'s Museum of African American History, the Montreal Tower and the Equinor building in Oslo.

In the Alps of Switzerland, Mike helps an elite team install a new cable (rope) system on an iconic mountain gondola line, helps fix the world's steepest cogwheel railway track and explores mountaintop family farms only accessible.

Going on a journey across Lithuania on big trains packed to the brim as massive ships wait to collect their bounty and take it across the ocean.

Exploring the design and engineering stories behind D.C.'s Museum of African American History, the Montreal Tower and the Equinor building in Oslo.

In the Alps of Switzerland, Mike helps an elite team install a new cable (rope) system on an iconic mountain gondola line, helps fix the world's steepest cogwheel railway track and explores mountaintop family farms only accessible.

Going on a journey across Lithuania on big trains packed to the brim as massive ships wait to collect their bounty and take it across the ocean.

A wolverine overcomes first-time flyer's nerves to travel to a new home. A helicopter pilot hunts for a showstopping ice cave. An 80-year-old cargo plane flies into the Arctic, and a wall of arctic fog threatens the airport wit.

The islands of Italy come in all shapes and sizes; they are home to volcanoes, ancient civilizations and some of the bluest waters on Earth.

A wolverine overcomes first-time flyer's nerves to travel to a new home. A helicopter pilot hunts for a showstopping ice cave. An 80-year-old cargo plane flies into the Arctic, and a wall of arctic fog threatens the airport wit.

The islands of Italy come in all shapes and sizes; they are home to volcanoes, ancient civilizations and some of the bluest waters on Earth.

A wolverine overcomes first-time flyer's nerves to travel to a new home. A helicopter pilot hunts for a showstopping ice cave. An 80-year-old cargo plane flies into the Arctic, and a wall of arctic fog threatens the airport wit.

Meandering through the black waters of a primordial river immortalized in a folk song.

Zoom in on some otherworldly sights; spot a giant glacier on the Red Planet, let the milky seas off the coast of Java bathe your vision, ponder a huge hexagon floating above Saturn and take a spin around a doughnut-shaped lake in Saskatchewan.

A journey on Scotland's River Spey, traveling from its source in the Highlands, winding by boat through the mountains to where the river meets the North Sea.

Explores strongholds abandoned by their architects; a lost city in the Amazon jungle; a desert fortress made by humanity's most notorious empire; explores a city of identical castles; examines a Greek isle's bloody history from the air.

Arctic conditions continue to wreak havoc in British Columbia; Jeremy Birch is called upon to raise a concrete-hulled vessel.

A journey on Scotland's River Spey, traveling from its source in the Highlands, winding by boat through the mountains to where the river meets the North Sea.

Explores strongholds abandoned by their architects; a lost city in the Amazon jungle; a desert fortress made by humanity's most notorious empire; explores a city of identical castles; examines a Greek isle's bloody history from the air.

Arctic conditions continue to wreak havoc in British Columbia; Jeremy Birch is called upon to raise a concrete-hulled vessel.

Retracing the steps of a German U-boat that's willing to do anything to replace its dwindling fuel and food stores, and get back to port; examining how the crew, plagued by scurvy, turns the tables on the US submarines that try to ram their ship.

A US sub shows unbelievable courage in the face of impossible odds. A look into how a bomb dropped by the Japanese forces pushes the craft into a deadly dive, and ignites a toxic chemical fire that leaves the crew fighting for their lives.

A wolverine overcomes first-time flyer's nerves to travel to a new home. A helicopter pilot hunts for a showstopping ice cave. An 80-year-old cargo plane flies into the Arctic, and a wall of arctic fog threatens the airport wit.

The islands of Italy come in all shapes and sizes; they are home to volcanoes, ancient civilizations and some of the bluest waters on Earth.

A wolverine overcomes first-time flyer's nerves to travel to a new home. A helicopter pilot hunts for a showstopping ice cave. An 80-year-old cargo plane flies into the Arctic, and a wall of arctic fog threatens the airport wit.

The islands of Italy come in all shapes and sizes; they are home to volcanoes, ancient civilizations and some of the bluest waters on Earth.

Witnessing the devastating impact of the German blitzkrieg as new tank strategies take the world by storm; learning how Germany overcame the inferiority of its panzers and swept through Poland and France with innovations in logistics and strategy.

New high-tech investigations uncover what sunk a World War I cruiser, a World War II submarine, a British destroyer from the Falklands War, and more.

Dictators may appear omnipotent, but their position depends largely on a network of individuals who benefit from their rule, and their support does not come cheap.

Witnessing the devastating impact of the German blitzkrieg as new tank strategies take the world by storm; learning how Germany overcame the inferiority of its panzers and swept through Poland and France with innovations in logistics and strategy.

New high-tech investigations uncover what sunk a World War I cruiser, a World War II submarine, a British destroyer from the Falklands War, and more.

Dictators may appear omnipotent, but their position depends largely on a network of individuals who benefit from their rule, and their support does not come cheap.

Witnessing the devastating impact of the German blitzkrieg as new tank strategies take the world by storm; learning how Germany overcame the inferiority of its panzers and swept through Poland and France with innovations in logistics and strategy.

New high-tech investigations uncover what sunk a World War I cruiser, a World War II submarine, a British destroyer from the Falklands War, and more.

A journey on Scotland's River Spey, traveling from its source in the Highlands, winding by boat through the mountains to where the river meets the North Sea.

Explores strongholds abandoned by their architects; a lost city in the Amazon jungle; a desert fortress made by humanity's most notorious empire; explores a city of identical castles; examines a Greek isle's bloody history from the air.

A journey along Ireland's longest river, the Shannon, through an emerald green landscape of rolling hills and sparkling waters; how Vikings, monks and kings have all made their mark.

Peek at landmarks in places where they shouldn't be; wing your way over an imperial pyramid in the Netherlands, a metal sphere in remote Russia, a lion shape carved into an English hillside and a bare swath cut through an Austrian forest.

Phil Risko's team at Northstar works fast to refloat a trawler that's been blown onto the shore of a national park in New Jersey; the team improvises to get it back to sea before it suffers further damage.

A journey along Ireland's longest river, the Shannon, through an emerald green landscape of rolling hills and sparkling waters; how Vikings, monks and kings have all made their mark.

Peek at landmarks in places where they shouldn't be; wing your way over an imperial pyramid in the Netherlands, a metal sphere in remote Russia, a lion shape carved into an English hillside and a bare swath cut through an Austrian forest.

Phil Risko's team at Northstar works fast to refloat a trawler that's been blown onto the shore of a national park in New Jersey; the team improvises to get it back to sea before it suffers further damage.

A look at the failures that forced a US submarine commander to rebuild his crew's trust, one person at a time; discovering how this commanding officer overcame dissent on board and refocused on targeting enemy ships in dangerous Japanese waters.

An American submarine crew gets an order: to hunt Japanese ships that are conducting a secret VIP evacuation in the Philippines in June 1945; examining the stealthy, dangerous tactics they used that would set a US Navy record.

Witnessing the devastating impact of the German blitzkrieg as new tank strategies take the world by storm; learning how Germany overcame the inferiority of its panzers and swept through Poland and France with innovations in logistics and strategy.

New high-tech investigations uncover what sunk a World War I cruiser, a World War II submarine, a British destroyer from the Falklands War, and more.

Dictators may appear omnipotent, but their position depends largely on a network of individuals who benefit from their rule, and their support does not come cheap.

Witnessing the devastating impact of the German blitzkrieg as new tank strategies take the world by storm; learning how Germany overcame the inferiority of its panzers and swept through Poland and France with innovations in logistics and strategy.

New high-tech investigations uncover what sunk a World War I cruiser, a World War II submarine, a British destroyer from the Falklands War, and more.

Dictators may appear omnipotent, but their position depends largely on a network of individuals who benefit from their rule, and their support does not come cheap.

Challenges beset a sculptural new transportation hub for New York's World Trade Center; Amsterdam gains a building inspired by a mountain valley; a new launchpad for space travel prepares for liftoff in the New Mexico desert.

Visiting the heart of history in the Dahshur necropolis, where the first of the great pyramids was built; examining what a mini-scanner called a LiDAR reveals about this landmark's enduring mysteries.

Follow the meteoric rise of the Macedonian conqueror who seized Egypt and built an empire that stretched from Europe to Asia; find out how founding the city of Alexandria and becoming a pharaoh transformed Alexander's life before his death at age 32.

Challenges beset a sculptural new transportation hub for New York's World Trade Center; Amsterdam gains a building inspired by a mountain valley; a new launchpad for space travel prepares for liftoff in the New Mexico desert.

Visiting the heart of history in the Dahshur necropolis, where the first of the great pyramids was built; examining what a mini-scanner called a LiDAR reveals about this landmark's enduring mysteries.