The remains of a deserted steamboat sit rusting beside an old ferry pier and an abandoned train platform.

An abandoned car and strange wooden debris are among the scattered remains of the old sand and gravel quarry.

A unique piece of graffiti offers a little slice of local history and mystery.

It is locally loved and ridiculed for literally looking like poop.

A statue commemorate Tommie Smith and John Carlos's brave protest at the 1968 Olympics, a watershed moment for civil rights.

An extensive collection of ancient Egyptian artifacts and mummies.

A restored 1920s cascade stairway provides one of the best views of Oakland's Lake Merritt.

This quirky roadside attraction dives into the many theories surrounding North America's most infamous hairy cryptid.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

An abandoned Cold War missile radar site.

Forgotten and then destroyed by fire, this was once one of the largest saltwater swimming pools in the world.

Lovers proclaim their unbreakable bond by leaving their names on locks fastened onto the Shoreditch fence in East London.

Artists and musicians now rule over this former rail station.

A hands-off space for graffiti artists to hone and display their skills.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

A walk down memory lane in the heart of one of San Francisco's most notorious neighborhoods.

Tenacious mummies survived dental problems, eternal entombment, and more than their fair share of devastating fires.

Alleyway plaque commemorating the death of a fictional character in The Maltese Falcon, not far from the author's home.

Created in 1972, the famous sculptor's intricately detailed monument to San Francisco is overflowing with city landmarks.

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.

A psychedelic labyrinth on the San Francisco bay.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.