A 300-ship graveyard, with a few still visible at low tide.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

A winding path built in secret on the edge of the continent.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

France's most famous cemetery, with some of its most curious tombs.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

Sitting beneath an unremarkable residential building is a museum devoted to classic Pinball.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

Budapest's Communist-era statues, banished to the suburbs.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.