This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

Breathtaking and huge 430 year old maps of Italy.

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

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

Macabre astrological automaton clock dating to the late 1400s.

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

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

This museum houses an imposing skeleton army comprised of creatures great and small.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

The oldest stone house in Paris was built by its most famous alchemist.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

Swarovski's museum/theme park is a fake diamond fantasia overlooked by a giant.

Archduke Ferdinand II's collection of rare objects is considered one of the oldest museums in the world.

This splendid tomb may look fantastic, but there's nothing in it...

Devilish masks, handicrafts, and pieces of old buildings create a snapshot of life in a historic Alpine region.

Factory that once supported an entire company town of 350.