Possibly the world's oldest rug, this Egyptian relic is woven entirely from ancient cat hair and once carried a mummified human foot.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

A tribute to Ponce de Leon's supposed quest for eternal youth.

Arrr! The most authentic collection of pirate artifacts in the world... matey.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

These caves secretly held national treasures during World War II.

Where commuters walk through remnants of an ancient Greek necropolis.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

An ancient octagonal weather station named for the eight Greek gods of wind.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

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

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

The Neapolitan Cult of the Dead still cares for the skulls at this mini-Fontanelle.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

This Delaware River bridge is emblazoned with a catty slogan from a more prosperous time.

The final resting place of many of New Jersey's most famous residents, including U.S. history's most in-vogue antagonist, Aaron Burr.

Nassau Hall has served as army barracks, a museum, and played a key role in the American Revolution.

The mysterious canine hides atop a drain pipe on the back of the building, some say as a sneaky shoutout to Yale.