Series of underground houses inhabited continuously for centuries.

This army of concretions is an unexplained geological phenomenon unlike anything else in the world.

This French "sea of rocks" is packed with stunning rock formations and its own medieval castle.

A unique underground structure dating back to the 1st century BC.

This fascinating abbey is considered the oldest monastery in the region.

An often-shuddersome journey into a low-tech, robotic themepark.

One of the largest ochre quarries in the world, hidden in a limestone landscape.

One man's desire to transcend art led to the construction of this outsider chapel.

For centuries, this large Roman villa remained hidden thanks to the eruption that buried nearby Pompeii and Herculaneum.

Abandoned cemetery of the former Psychiatric Hospital of Volterra.

An abandoned bell tower in the middle of nowhere is the last testimony of a forgotten medieval village.

A medieval stronghold rising over the ruins of ancient Roman villas along Rome's southern coast.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

Abandoned village in Sicily built during the agricultural reforms of Mussolini.

This skeletal, unfinished Gothic church once housed a miraculous masterpiece by Raphael.

Take a giant yellow bird cage to the top of Elba's highest mountain.

Next to the Leaning Tower of Pisa is a cemetery home to ancient sarcophagi and disturbing murals.

This former fascist summer camp was abandoned for decades.

The “Sistine Chapel” of the Middle Ages merges 11th-century science and religion in wondrous hues.

This scenic fortress dates back at least 2,400 years to the time of Magna Graecia.

A fascist-era rural village abandoned since the early 1980s.

A medieval fresco which reminds visitors that death will come for us all.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

An unusual house built using an iso-elastic membrane.