Visible below the waves are memorials to the city's Gold Rush dead.

This small, unassuming street is now a canvas for color and creativity.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

A tunnel with windows, so you don't miss out on the impressive views.

Original cabaret handbills, posters, and feline artwork are a purrfect highlight of the Museum of Montmartre.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.