A suspended footbridge allows for traversing this gorge carved through the French Alps.

Resting on a hill overlooking the coast, these medieval ruins look completely deserted save for their restored chapel.

Series of underground houses inhabited continuously for centuries.

Tens of thousands of ancient rock carvings hidden in the heart of a French national park.

This modern museum of Mediterranean culture is surrounded by a surreal concrete honeycomb.

This narrow path was cut right into a French mountainside to feed the country's early naval expansion.

A chapel on a volcanic core, marking the end of a successful journey.

An ancient monastery, a locked room, and a mysterious book heist.

A public park off the beaten path with a beautiful waterfall and 13th century Cistercian abbey.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

A medieval military street hidden beneath a charming French fishing village.

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

An icy lake tucked among jaw-dropping alpine panoramas.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

This salt marsh in Southern France is as pink as the flamingos that inhabit it.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

Ancient paintings known as the "Sistine Chapel of Cave Art."

This preserved wilderness hides the remains of a colonial grain mill used to feed George Washington's troops.

This city park was once a lookout point for George Washington’s army during the Battle of Brooklyn in 1776.

A decommissioned military complex that's now a modern industrial park.

This secluded ruin was once a home for exotic plants.

Every animal in the torah taxidermied and crammed into a Brooklyn townhouse.

A way to take your secrets to someone else's grave.