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.

A massive, secret marina for the Nazis' most formidable weapon in the Atlantic.

Green labyrinth formed by a karstic maze hidden in a preserved oak forest.

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

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

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

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

The 16th-century church was kept in its ruined state as a reminder of the casualties of World War I.

This ancient theater was once the home of fierce gladiatorial battles.

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

A medieval church with largest and oldest collection of Renaissance frescoes in France.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

Since ancient times these picturesque springs have been providing bathers with healing waters.

This medieval tower is all that remains of the castle where Joan of Arc was held before being burned at the stake.

Dedicated to the art of hunting, with juxtapositions of contemporary art.

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

This recessed garden protects thousands of mountain plants by creating its own microclimates.

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

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

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

Ivy-covered Medieval tunnels cut through this charming town in France's Loire Valley.

An aluminum skeleton brings Chinese mythology to the French shore.

This Parisian gem is one of the most incredible ethnographic museums in the world.