Structure built from the skulls of vanquished foes.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

A Red Cross memorial museum at the site of the Niš concentration camp that operated for four eventful years during World War II.

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

Get past the gatekeeper's apartment and enter an elaborate hoax of a restaurant with a Masonic feel.

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

One part local history, 99 parts gruesome haunted house.

A hidden art gallery in an abandoned Warsaw fort.

This cemetery features modernist statues as strange as its name.

A temple to modernity, tucked away amid Barcelona's more well known museums.

18th century anatomical amphitheater of the Royal College of Surgery of Barcelona.

The studio of Catalonia's most famous theatrical designer remains exactly as he left it.

This Funeral Hearse Museum represents the finest in cadaver transportation.

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.

Some say this medieval church is where the poet Dante married his wife and also met the love of his life.

An incredible menagerie of more than 3 million taxidermied animals at the oldest science museum in Europe.

This museum is rotten with a century of wax medical deformities.

This crumbling, graffiti-covered mansion sits tantalizingly within reach of the proletariat who frequent a public park.

A stunning 18th century pharmacy and medieval chemist's collection.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

This solitary monastery may hold the remains of Vlad the Impaler (but probably not).

Ottoman-era houses lovingly preserved.

A marvel of Byzantine engineering under the streets of Istanbul.

This museum was invented in a novel before being made real by the author.