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

Remains of a station that only operated for one year.

A fortress built to pacify local uprising that had a stint as a Nazi concentration camp before becoming a five-star hotel.

This Ukraine alleyway has become its own little island of forgotten things.

A peculiarly shaped brass sculpture hidden in a courtyard in central Lviv

A quirky collection flush with information on commode culture from ancient times to modern day.

Monumental sculptures guard many of the graves, transforming this necropolis into an open-air fine art museum.

A Kyiv-based repository for all manners of discarded curiosities.

This Ukranian fortress is one of the best-preserved medieval castles in Europe.

This oddly shaped building is a surprising Soviet-era crematorium.

This exquisite, alienesque piece of Soviet architecture is being threatened by modern shopping malls.

The ruins of an abandoned church loom within a picturesque Ukranian village.

The largest park in Lviv is surrounded by a network of disused rail tracks.

This underground transport hub doubles as an art gallery.

Welcome to the world's only museum dedicated to the Ukranian Easter egg.

This derelict superstructure was a very important warning system for the Soviet military.

A subterranean Holocaust refuge within one of the world's longest cave systems.

One of the most poignant ruins of the Chernobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

The largest catacomb system in the world.

This attraction was abandoned after the Chernobyl disaster.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.