A 140-year-old castle with underground caves hidden in San Francisco.

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

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

A psychedelic labyrinth on the San Francisco bay.

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

A huge musical instrument played by the ocean.

A "Minnesota-style" pizza parlor in the Scandinavian heart of Seattle.

A Boeing mechanic and his wife leave a whimsical, stone sculptured garden as their legacy.

A commemorative mural in this tiny Ballard park honors the neighborhood's rich Scandinavian ties, particularly with Seattle's Norwegian sister city Bergen.

An old-timey peepshow allows visitors to gawk at some of the world's most freakishly large footwear.

A nondescript Seattle restaurant inherited a piece of European history.

The flock of plastic poultry is an ode to the classic comedy staple.

This Seattle store is packed with all sorts of curious creatures and creations.

A sliver of nostalgia in Seattle's Viretta Park.

This historic building provides a powerful glimpse into the lives of Japanese Americans forced to relocate during World War II.

Residents of Fremont in Seattle have considered it the center of the universe since the 1970s.

A beautiful final resting place for some of the noteworthy deceased.

A wall of chewing gum moonlights as collective art.

A huge musical sculpture and other art installations on the National Oceanic and Atmospheric Administration grounds.

Make your reservation to have coffee with some kitties.

A museum dedicated to the history and exploration of both popular music and science fiction.

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

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

The site of the first couple's first kiss is commemorated by the most adorable presidential monument ever.