Two stone columns flank the grand Venice square, but there were supposed to be three.

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

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

Many famous English poets including Elizabeth Barrett Browning are laid to rest at this Swiss-owned cemetery in Florence.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.

A series of playful yellow penguins share a serious message about the environment.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

The capital of the Cayman Islands is a center of offshore banking, but gets battered by blistering hurricanes.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

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

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

Two small markers remember the Alamo's feline protectors.

A small peaceful park and waterfall tucked amid the urban grind of Midtown Manhattan.

Elevated freight railway turned wildly successful urban park.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

This working class sculpture pounds his hammer all the livelong day.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

A white oak with property rights.

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

It was once the base for a series of domestic terror attacks.

There’s a hidden military meme engraved on the World War II Memorial.

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