The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

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

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

America's first nuclear-powered merchant ship is now a time warp to the atomic age.

Three abandoned missile silos are hiding in plain sight behind a suburban development in Maryland.

Electronic inventions that resulted in products and systems we use every day are on display in this labor-of-love museum.

A lawn full of retired spacecraft on display at one of NASA's first research labs.

Two dozen pinball games hidden away inside a most unlikely location.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

The shelves in the back of this thrift store are devoted to saving, not selling, retro tech.

Walk a trail through a historic Quaker town that outlawed slavery in 1777 and was a major waypoint on the Underground Railroad.

A priceless collection of the Nation's cryptologic history.

This free, take-a-book shop seems like a trick but isn't.

Eighteen miniature death-scene dioramas.