This subterranean necropolis holds three floors of antler-dug grave caves.

Europe's oldest still-operational tea farm also boasts a spectacular view.

A brick arch is all that remains of this Dutch fort, once a focal point for colonial power struggles in Guyana.

The largest art park on the European continent.

Replica of mosque destroyed by Russia in the 16th century.

Hidden in a metro shop under a shopping mall, this small museum tells the story of one of the world's largest urban transit systems.

Folky pharmaceuticals abound in this medicinal reliquary.

This artificial archipelago was supposed to resemble a map of the world.

Once the foundation for a mansion, these ruins now offer amazing panoramic coastal views.

An enormous, 30-story-deep hole in the middle of Guatemala City.

A tower marking the spot where Yugoslavia began its resistance against the invading Nazis stands neglected, but not quite forgotten.

This Greek temple, open only an hour a day, was the site of a war of tastes between an architect and an artist.

This picturesque medieval monastery guards a small trove of historic treasures.

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

Double spiral staircases are not unheard of, but they are very rare.

Once a state-of-the-art tuberculosis treatment spa, these ruins are now ruled by paintball players.

A small marionette collection located within the dark cellars of an 11th-century Austrian castle.

The topiary maze at the Habsburg hunting lodge.