The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

The last bastion of Roman presence north of the Alps looms over a German town.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

One of the world's oldest universities houses an incredible collection of anatomical models, mummified body parts, and human bones.

The morbid items in this small and hidden museum are not for the weak stomached.

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.

A subterranean shelter remains intact under a busy Paris railway station.

Medical history with an amazing, if frighting, collection of wax diseases on display.

France's national museum of scientific and industrial instruments.

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

Perhaps the most spectacular grotto along the Algarve coastline.

An early Portuguese serial killer's head is alarmingly well preserved in a jar at the University of Lisbon.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

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

This unreal Portuguese palace looks as though it's made from a pile of different castles.

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

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A haunting collection of the vanished and disappearing natural world.

This Funeral Hearse Museum represents the finest in cadaver transportation.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

France's most famous cemetery, with some of its most curious tombs.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.