This historic estate on the east shore of Lake Tahoe was home to an eccentric millionaire (and his pet elephant, Mingo).

This labyrinthine resting place of Black American leaders has been reclaimed by nature.

Volcanic stone sentinels stand watch at a Korean Bell Garden in Virginia.

The only place for a truly presidential dram.

A small, forgotten prison cemetery marked only by a wrought-iron fence and eerie depressions left in the ground.

A lone historical marker off the highway and scattered debris are all that remain of this Cold War-era missile site.

A 14-foot monument marks the resting place of two of the town's earliest residents—and one unknown soldier.

This museum dedicated to divination also honors a local 10th-century prophetess.

A tiny collection of traditional Japanese woodblock prints, open only when the owner feels like it.

A celebrity from the late Cretaceous period.

This poor little statue is the most vandalized memorial in Washington.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

A super-sized promotional trick that is now a D.C. landmark.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

This leafy estate is worth $18 million and is so grand it has two mailing addresses.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

A painfully obvious spy house sits right across the street from the Russian Embassy.

A derelict bit of transportation infrastructure hidden in the woods.

A historic neighborhood church is reborn as a psychedelic arts collective.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

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

The site of the climactic scene from the classic horror film is now a historic landmark.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.