Gladiators once walked this ancient, subterranean passage.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

According to myth, Zeus himself was hidden in this cave to escape being eaten by his dad.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

This one-time health resort was used by aristocrats around the world.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

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.

The house where Robert E. Lee planned the Battle of Antietam is said to be haunted by the ghost of a Civil War soldier.

A historic presidential getaway on the continental United States' southernmost island.

An idyllic swimming pool tells the tale of Hemingway's trouble with women.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

A monument celebrating the idea of reaching inaccessible places.

The sign that drew attention to a young boy's cucumber stand is now the name of his fruit superstore.

Visit Europe's largest subterranean waterfall, carved by water from the glaciers of the towering peaks surrounding the valley.

A historic observatory precariously perched at the "Top of Europe."

This scenic spot is known as the birthplace of Switzerland.

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

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

A futuristic rocket marks the spot where three borders meet.

The smallest museum in Basel, Switzerland, is a two-foot-by-two-foot window in the door of a 600-year-old house.

The most impressive of Basel's three remaining city gates.