Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

Venice's island of the dead.

Venice's "Island of the Mad."

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

One of the largest ancient geoglyphs in the world is a tall desert god used for predicting the weather.

The world's second-largest sundial, made entirely out of stone.

An elaborate shrine dedicated to the four corners of the world unfortunately misses its mark.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

Serbia's master of striking memorials erected a forgotten, hidden gem in the hills outside a tiny village.

Take a sea tractor to the Art Deco hotel on the island that inspired Agatha Christie.

The legend says that this English rock formation was once a hunter who was turned to stone by annoyed witches.

Legend says these rocks used to be hunting dogs, a story that may have inspired Sherlock Holmes' most famous case.

The largest greenhouse in the world is home to over one million types of plants.

Giant naked man on a hillside.

A kaleidoscopic warehouse-maze of handmade neon signs.

A tongue-in-cheek arcade where the games are based on everyday life.

The small cliffside monastery known as the Tiger's Nest is said to be the meditation site of an 8th-century Buddhist master.

This penis-focused monastery is dedicated to Buddhism's "Divine Madman."

The small sanctuaries lie just off the beaten path near one of Bhutan's most famous attractions.

This giant Buddha statue has 125,000 smaller Buddhas hidden inside it.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

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