Tiny communists hammer away on the Olomouc Astronomical Clock.

A museum of alchemy and a basement laboratory all housed in an ancient building in a Gothic tower.

A church of bones, decorated with 40,000 human skeletons.

A Hungarian pharmacy museum with a box full of mummy powder.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

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

Famously misunderstood wonder of the ancient world

Recently restored menagerie of Victorian-era beasts.

Repository for more than 22 million pickled specimens.

Charles Babbage's proto-computer, painstakingly brought to life.

Scattered throughout London are ancient remnants of the city's former bounding wall.

Rebuilt remains of a temple to Roman god Mithras.

The monster at the center of the Darwin Center Spirit Collection.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

A friendly pub with a sordid past in cock fighting.

Louise Bourgeois' 30-foot-tall steel spider sculpture.

The anatomical-pathological collection of a man who changed surgery.

This small chapel is built of human bones and decorated with a golden skeleton.

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

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

A cemetery for Slovenian notables also serves as a popular recreation space.