This century-old roadside attraction is full of bizarre rock formations.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

This former quarry is now a picturesque gorge that hides a sunken lake.

A spiral staircase twists to the top of this unusual Czech lookout tower.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

A beautiful but toxic fountain of mercury.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.

This semi-secret storybook hedge maze is also the oldest garden in the city.