A flooded Mexican cave that hides a river beneath the water.

A more than 260-year-old crypt built on Boston's oldest English burial ground.

Hidden inside this Arizona fast food franchise is an in-depth exhibit on the famed WWII counterintelligence program.

The future of roadside attractions is this sci-fi soda mecca that is home to a 66-foot tall neon pop bottle.

The Magical World of George Phar Legler.

The towering figures were created from the cemetery's fallen old-growth trees.

This historic structure has been used as a mosque, a barracks, a prison, a school, and a bakery.

The ruins of this once gorgeous medieval church are still standing, despite the region's constant flooding.

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

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

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

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

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

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

Home to items never before seen by the public.

Legend has it the commander of the defenders drew a fateful line in the dirt with his sword just before the final battle.

A four story, football field-sized, nine-grotto creation made of shells, minerals, and rare stones.

Step back in time at this 1950s display home, built to showcase once cutting-edge electric amenities.

An acoustic anomaly with a mysterious cause.

Museum dedicated to awful artwork.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

Go inside to really appreciate this 500-year-old technological masterpiece.

A whale rib was used to advertise the store by the arch that offered exotic goods from far away.