A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

Formerly known as National D-Day Museum, this collection commemorates the battles of Normandy and WWII.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

A mocking tribute to the past and modern leadership of Prague.

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

The highest point in Washington state is a volcano covered in glaciers.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

This replica of the Greek structure is in the heart of Nashville.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

A celebration of capitalism in Midtown.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

Mysterious 500-year-old tapestries depict a unicorn hunt.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

Take a drunken tour inside the world's largest known geode.

A dilapidated dock tells the story of Titanic's missed arrival.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

An abandoned network of military bunkers and tunnels open for anyone willing to descend into the darkness.

Yo, Adrian!

These lush botanical gardens employ the most purrfect pest control force.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.