Discover an ancient secret that dates back to the dawn of time lurking beneath the city of Budapest, Hungary. The caves beneath Budapest were formed during the Ice Age and everyone from cavemen to communists has moved their city into the depths of this parallel world. Join host Eric Geller as he gains special access into this sealed-up time capsule where he'll uncover a top secret World War II hospital, find the source of the boiling healing water used by both the Romans and the Turks, and see the layers of support added throughout the centuries to keep today's world from falling into the one buried below. Watch as the technological marvels that allowed construction of one city upon another are revealed.

Naples, Italy narrowly escaped meeting the same fate as its neighboring city, Pompeii in 79 AD when Mount Vesuvius wiped out everything around it. The wind saved Naples that day, but life in the shadow of this massive volcano is unlike any other--and so is its underground. For centuries, Neapolitans have carved out their underground, creating a parallel world where their secrets are safe. Entire neighborhoods line the underworld, time capsules of ancient life--with banks, bakeries, and homes preserved below. From repelling into an ancient Greek cavern to uncovering Nero's famous stage underneath a modern apartment, host Don Wildman steps back almost 2,000 years to discover the world hidden beneath this volcano.

Edinburgh, Scotland is a thriving metropolis, but take a look into its past, and you'll find it has led a double life. A sophisticated and educated surface city evolved above while a darker, seedy world grew below--from plague victims getting buried alive under the streets to body snatchers, illegal distilleries, and castle dungeons. Join host Eric Geller as he investigates these stories, deciphering fact from fiction, while uncovering the engineering marvel of Edinburgh's underground--created when the city actually changed its street level.

World War I was the bloodiest war the world had ever seen. A young Adolf Hitler served in the trenches and tunnels of Belgium's Western Front. Join host Don Wildman as he explores the subterranean web where 24,000 Allied soldiers waited to ambush the enemy, to the indestructible fortress that endured thousands of bombs daily. Discover the underground that made World War I one of the most brutal wars in history... and turned Hitler into the terrifying madman of World War II.

Berlin, Germany was the battlefield of the 20th century, and today, sealed up and forgotten beneath its streets are the remnants of a dark past. Walk anywhere in the city and you could be walking directly on top of one of the over 1,000 Nazi bunkers engineered into Berlin's sandy soil, lost remnants of Hitler's ill-fated Germania or even beer brewing plants that inspired the Nazis' journey into the underground.

Prague is a city cloaked in mystery, with an underground to match. Medieval castles line the streets and hide dark dungeons deep below them. From quarries where Hitler may have stored his most powerful secret weapon to mines that doubled as Communist slave camps, Prague has surprising stories to tell. Join host Don Wildman as he reveals the technological marvels that allowed the construction of one city upon another--literally.

The largest naval armada in U.S. history descended on the Japanese island of Okinawa in April of 1945. Instead of a swift victory for the Americans it became the bloodiest battle of the Pacific. Much of the battle wasn't on land. It was underneath it--from the beehive of combat tunnels to the caves where thousands of civilians hid. Join host Don Wildman as he discovers what it was like to live through the Battle of Okinawa. Watch as he delves into the subterranean tunnels, caves, and bunkers, and then dives to explore the lost naval destroyer sunken deep in the waters off Okinawa's coast.

Dublin, Ireland is much more than a city full of pubs and pints. Pagan burial tombs, subterranean defense tunnels, and mysterious burial crypts line the underground below the rolling hills. Even an underground river runs through the heart of the city where you'd least expect to find it.

Discover an ancient secret that dates back to the dawn of time lurking beneath the city of Budapest, Hungary. The caves beneath Budapest were formed during the Ice Age and everyone from cavemen to communists has moved their city into the depths of this parallel world. Join host Eric Geller as he gains special access into this sealed-up time capsule where he'll uncover a top secret World War II hospital, find the source of the boiling healing water used by both the Romans and the Turks, and see the layers of support added throughout the centuries to keep today's world from falling into the one buried below. Watch as the technological marvels that allowed construction of one city upon another are revealed.

Naples, Italy narrowly escaped meeting the same fate as its neighboring city, Pompeii in 79 AD when Mount Vesuvius wiped out everything around it. The wind saved Naples that day, but life in the shadow of this massive volcano is unlike any other--and so is its underground. For centuries, Neapolitans have carved out their underground, creating a parallel world where their secrets are safe. Entire neighborhoods line the underworld, time capsules of ancient life--with banks, bakeries, and homes preserved below. From repelling into an ancient Greek cavern to uncovering Nero's famous stage underneath a modern apartment, host Don Wildman steps back almost 2,000 years to discover the world hidden beneath this volcano.

Edinburgh, Scotland is a thriving metropolis, but take a look into its past, and you'll find it has led a double life. A sophisticated and educated surface city evolved above while a darker, seedy world grew below--from plague victims getting buried alive under the streets to body snatchers, illegal distilleries, and castle dungeons. Join host Eric Geller as he investigates these stories, deciphering fact from fiction, while uncovering the engineering marvel of Edinburgh's underground--created when the city actually changed its street level.

World War I was the bloodiest war the world had ever seen. A young Adolf Hitler served in the trenches and tunnels of Belgium's Western Front. Join host Don Wildman as he explores the subterranean web where 24,000 Allied soldiers waited to ambush the enemy, to the indestructible fortress that endured thousands of bombs daily. Discover the underground that made World War I one of the most brutal wars in history... and turned Hitler into the terrifying madman of World War II.

Berlin, Germany was the battlefield of the 20th century, and today, sealed up and forgotten beneath its streets are the remnants of a dark past. Walk anywhere in the city and you could be walking directly on top of one of the over 1,000 Nazi bunkers engineered into Berlin's sandy soil, lost remnants of Hitler's ill-fated Germania or even beer brewing plants that inspired the Nazis' journey into the underground.

Prague is a city cloaked in mystery, with an underground to match. Medieval castles line the streets and hide dark dungeons deep below them. From quarries where Hitler may have stored his most powerful secret weapon to mines that doubled as Communist slave camps, Prague has surprising stories to tell. Join host Don Wildman as he reveals the technological marvels that allowed the construction of one city upon another--literally.

The largest naval armada in U.S. history descended on the Japanese island of Okinawa in April of 1945. Instead of a swift victory for the Americans it became the bloodiest battle of the Pacific. Much of the battle wasn't on land. It was underneath it--from the beehive of combat tunnels to the caves where thousands of civilians hid. Join host Don Wildman as he discovers what it was like to live through the Battle of Okinawa. Watch as he delves into the subterranean tunnels, caves, and bunkers, and then dives to explore the lost naval destroyer sunken deep in the waters off Okinawa's coast.

Dublin, Ireland is much more than a city full of pubs and pints. Pagan burial tombs, subterranean defense tunnels, and mysterious burial crypts line the underground below the rolling hills. Even an underground river runs through the heart of the city where you'd least expect to find it.

Discover an ancient secret that dates back to the dawn of time lurking beneath the city of Budapest, Hungary. The caves beneath Budapest were formed during the Ice Age and everyone from cavemen to communists has moved their city into the depths of this parallel world. Join host Eric Geller as he gains special access into this sealed-up time capsule where he'll uncover a top secret World War II hospital, find the source of the boiling healing water used by both the Romans and the Turks, and see the layers of support added throughout the centuries to keep today's world from falling into the one buried below. Watch as the technological marvels that allowed construction of one city upon another are revealed.

Naples, Italy narrowly escaped meeting the same fate as its neighboring city, Pompeii in 79 AD when Mount Vesuvius wiped out everything around it. The wind saved Naples that day, but life in the shadow of this massive volcano is unlike any other--and so is its underground. For centuries, Neapolitans have carved out their underground, creating a parallel world where their secrets are safe. Entire neighborhoods line the underworld, time capsules of ancient life--with banks, bakeries, and homes preserved below. From repelling into an ancient Greek cavern to uncovering Nero's famous stage underneath a modern apartment, host Don Wildman steps back almost 2,000 years to discover the world hidden beneath this volcano.

Edinburgh, Scotland is a thriving metropolis, but take a look into its past, and you'll find it has led a double life. A sophisticated and educated surface city evolved above while a darker, seedy world grew below--from plague victims getting buried alive under the streets to body snatchers, illegal distilleries, and castle dungeons. Join host Eric Geller as he investigates these stories, deciphering fact from fiction, while uncovering the engineering marvel of Edinburgh's underground--created when the city actually changed its street level.

World War I was the bloodiest war the world had ever seen. A young Adolf Hitler served in the trenches and tunnels of Belgium's Western Front. Join host Don Wildman as he explores the subterranean web where 24,000 Allied soldiers waited to ambush the enemy, to the indestructible fortress that endured thousands of bombs daily. Discover the underground that made World War I one of the most brutal wars in history... and turned Hitler into the terrifying madman of World War II.

Berlin, Germany was the battlefield of the 20th century, and today, sealed up and forgotten beneath its streets are the remnants of a dark past. Walk anywhere in the city and you could be walking directly on top of one of the over 1,000 Nazi bunkers engineered into Berlin's sandy soil, lost remnants of Hitler's ill-fated Germania or even beer brewing plants that inspired the Nazis' journey into the underground.

Prague is a city cloaked in mystery, with an underground to match. Medieval castles line the streets and hide dark dungeons deep below them. From quarries where Hitler may have stored his most powerful secret weapon to mines that doubled as Communist slave camps, Prague has surprising stories to tell. Join host Don Wildman as he reveals the technological marvels that allowed the construction of one city upon another--literally.

The largest naval armada in U.S. history descended on the Japanese island of Okinawa in April of 1945. Instead of a swift victory for the Americans it became the bloodiest battle of the Pacific. Much of the battle wasn't on land. It was underneath it--from the beehive of combat tunnels to the caves where thousands of civilians hid. Join host Don Wildman as he discovers what it was like to live through the Battle of Okinawa. Watch as he delves into the subterranean tunnels, caves, and bunkers, and then dives to explore the lost naval destroyer sunken deep in the waters off Okinawa's coast.

Dublin, Ireland is much more than a city full of pubs and pints. Pagan burial tombs, subterranean defense tunnels, and mysterious burial crypts line the underground below the rolling hills. Even an underground river runs through the heart of the city where you'd least expect to find it.