Live out your childhood construction fantasies in this one-of-a-kind gyrating hotel.

The largest flower auction house in the world.

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

This abandoned Belgian fortress is purposefully being left to nature.

Hiding the longest subterranean river known in the world.

This splendid tomb may look fantastic, but there's nothing in it...

Where beer lovers can literally immerse themselves in beer.

The stones of this formerly witch-obsessed castle were used to build a church.

Brussels' favorite peeing boy has a sister.

The tiny Belgian town's ancient version of Mardi Gras involves eerie wax masks, sticks for warding off evil, and ostrich plume hats.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

This "floating railway" is one of the world's oldest monorail systems.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

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

An elegant chandelier hangs over this ancient sewer chamber, now open for concerts and public tours.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Bold black and white motifs of life and death add a dramatic flair to this 17th-century crypt.

This abandoned mansion has a window for every day of the year, and is a temple for ghost hunters.

An eccentric collection of antique items shares space with a prop-quality witchcraft museum.

A contemporary art installation housed within a Gothic cathedral.

A landscape decorated with enormous skull sculptures.