A giant Troll lurks under one of Seattle's oldest bridges.

This 13th century Gothic brick castle is the largest in the world by surface area.

A haunting deserted hotel is a favorite with artists and photographers.

A collection of old neon signs from all over Poland line a secluded courtyard.

The silly symbol for an underground protest group is now scattered around the city.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

A lush indoor jungle fills this bustling Madrid transportation hub.

A rococo retro-futurist future-rustic vernacular between yesterday’s tomorrow and the future that never was.

Sitting atop San Francisco's tallest hill, a cross honors the victims of the Armenian genocide.

The neighborhood church casts a breast-shaped shadow that locals have come to call the “two o’clock titty.”

A modest reminder of treacherous waters at the Golden Gate.

Art in the form of a winding, man made crack in stone.

This one-block alleyway is stuffed with street art that is colorful, cultural, and intensely political.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

This print shop boasts one of the largest pinball arcades in San Francisco.

Recovered from the brink of extinction, at home in the Financial District.

Radioactivity still cause for concern at this urban explorer's paradise.

A man-made island in scenic San Francisco Bay.

An overlooked and unassuming engineering marvel.

The miraculous hydrant that saved the Mission District in 1906.