Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

Gigantic Romanian salt mines used to heal respiratory conditions.

This massive underground salt mine now holds a sci-fi theme park in its depths.

An underground city of salt.

Most-visited and most-photographed slot canyon in the American Southwest.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

Lavish royal estate punctuated with heated greenhouses.

Take a leisurely walk through the park to find the seven giant troll sculptures hidden throughout the park.

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

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

Historic medieval fortified city in southwest France.

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

This crack in France's seaside cliffs once hid a sinister secret.

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

This 12th century, partially destroyed, abbey has had several owners and was seized during the French Revolution.

The smallest port in France is named after the pirate who created it.

A small museum of antique transport that's a must-see for bicycle lovers.

A bike train runs along a disused railway line through the tranquil French countryside.

An enchanting work of outsider art, full of whimsical sculptures and carvings.

On this romantic tidal island reachable only at low tide the tomb of a famous French writer overlooks the sea.

The famous winding walk at Chartres is surrounded in mystery and myth.

A self-built mosaic house and sculpture park.

A beautiful lighthouse with as many steps as days in the year, as many windows as weeks, and as many levels as months.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.