A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

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.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

The unedited photograph called "Bliss" has graced the screens of over a billion computers.

The dramatic upward-curving roof is one of the most iconic examples of Googie architecture that still stands today.

A deserted hodgepodge of experimental structures designed by nearby university students.

One of the earliest bowling lanes in the U.S. doubled as a sewing school during a time when women had little job opportunity.

The remains of an abandoned dinosaur theme park litter the woods just off the highway.

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

The Virginia home of one of the signers of the Declaration of Independence is being preserved with a unique glass facade.

Stumbling upon this whimsical wooded garden is like stepping into an enchanted forest full of philosophical musings.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

A collection of over 2000 air-moving devices of all kinds displayed in the Fanimation headquarters.

Go through the looking glass in Tokyo's Wonderland-themed shop.

The rogue roots are gradually consuming some of the historic marble grave markers.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

There's a crumbling old mansion inside the Smithsonian National Zoo.