These unusual rooms on wheels are holdovers from the 1960s.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

The "lovely red Vega" of the legendary record-settling pilot.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

Washington's iconic carousel has a nice piece of Civil Rights history.

Coins and medals straight from the mint await visitors to this shop in the nation's capital.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

Perhaps the most scandalous statue of America's first president.

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

Art Deco stylings conceal the true nature of this bridge.

This 14th-century temple is also known as the "Temple of the Golden Pavilion" for its gorgeous gilded reliquary hall.

Protecting the dead from opportunistic body snatchers.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

A sea cave with a waterfall and Viking past

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

Inside this art museum resides one of Glasgow's most famous musical instruments.

The fifth-longest natural arch in the world, and the longest outside China.

A tunnel with windows, so you don't miss out on the impressive views.

The unusual patterns in this rock formation result from two distinct modes of weathering.

10,000 flowered plants bloom in the City of Roses.

The magic's in the hole!