In this 400-year-old hotel in Madrid, you'll find a comb in every room, an old clock, and maybe a ghost.

These distorting, funhouse mirrors achieved fame in a renowned piece of Spanish theater.

Mary Kelly was last seen here before she was murdered by Jack the Ripper.

Giant, friendly pelicans in Central London, the most unlikely of places.

The bronze uniforms commemorate the vital role of women during World War II.

A haunting monument dedicated to the Royal Naval Air Service and the Fleet Air Arm.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

Order a salt beef-loaded beigel at any hour of the day or night at this East End institution.

Artists and musicians now rule over this former rail station.

A totem pole of heads to represent the different stages of life.

The largest of London's subterranean rivers and once a mad, bad center of London life.

A friendly pub with a sordid past in cock fighting.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

A mysterious suspended hand greets unsuspecting visitors at the Tower of London.

A doorless and windowless folly in England that evokes curiosity over its mysterious origins.

Twisted buildings adorn the banks of the Rhine river.

This futuristic German television spire is actually the world's largest digital clock.

On the Oregon coast there is a natural hole that seems to be draining the sea.

Most complete collection of Gymnosperms in the world.

Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

Stroll through a wonderland of stupendous moss-covered trees.

Two provinces and two territories touch borders deep in the middle of the wilderness.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.