A unique hotel for the artistic soul.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

An ancient knight and a symbol of the city's freedom.

Gargoyle head that brings good luck.

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

A tiny church on a man-made island in the Adriatic.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

A treasure trove of astronomical, mathematical, and scientific instruments at Cambridge University.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

An ornate plague column – built to celebrate life – claimed the lives of numerous artisans during its construction.

Man-made cave with enigmatic carvings, some say made by the Knights Templar themselves.

Vast fan-shaped British cemetery honouring American servicemen lost in World War II.

Venice's island of the dead.

100 year tradition of fist fights, marked by marble footsteps.

This massive subterranean fissure is known as the "underground Grand Canyon."

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

A whimsical bridge adorned with decorative dragons.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

Public access to clean drinking water was an instant hit among the masses.

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.