Obscure Freemasons still live in D.C.’s largest private residence.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

These abandoned grain silos and tunnels are an urban exploration dream.

Chicago's museum dedicated to the history of bondage and fetishism is more textbook than titillation.

An enormous park-like oasis, full of famous Chicagoans' graves.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

A lush green oasis in the middle of Chicago.

This shop for all your super spy needs hides an educational secret.

These towering spires and glowing walls are carefully crafted from hundreds of thousands of icicles.

Activists are fighting to preserve these unfinished highway ramps as a tribute to the citizen revolt that halted their construction decades ago.

This Seattle curio shop collects and sells haunted items in order to spread wonder one grim artifact at a time.

This historic hub for labor unions has survived the city's changing landscape.

This Cold War siren is one off the last of its kind still standing with its immensely powerful original horn.

Allowing humans and fish alike to migrate from freshwater to saltwater and back again.

Providing the soundtrack to the golden years of the Seattle grunge scene.

This grand old 80-foot sequoia towers above the buildings in the city’s retail center.

Statue of Lenin, from Cold War era Czechoslovakia, now in a neighborhood of Seattle.

A rotting tree in the middle of Seattle doubles as an elaborately-controlled art piece.

A "sinister, whimsical, tacky, and really orange" public art installation hidden under a Seattle bridge.

The first park built over a freeway is a brutalist masterwork.

This former coal gasification plant found a curious second life as a popular public park.

This semi-secret garden in south Seattle emulates a traditional Japanese garden using the plants of the Pacific Northwest.

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