This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

Walk 2,300 feet above the ground on the "Troll's Tongue."

Hundreds of hidden passageways weave through the old quarters of Lyon.

A Gothic cathedral created from volcanic rocks.

An eerie, derelict amusement park in Berlin.

Museum preserving torture methods from the past.

A former plague hospital turned medical museum.

A curious collection dedicated to human and animal anatomy and pathology.

The lost American era of gunfighters, bandits, Indians and steam trains is recreated in Sweden.

The second oldest anatomical theater is housed in a museum of curiosities.

For a couple of months each year this Swedish city turns into a festive neon phantasmagoria.

The world's largest model of our planetary system.

Terrifying derelict military hospital once housed a recuperating Hitler.

The largest underground church in Europe.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

Three million year old fossils are exposed for all to see on this Icelandic shore.

Staves, storm-calling, and of course, necropants.

A sulfuric martian landscape that looks far better than it smells.

The Icelandic Sea Monster Museum explores the area's history of aquatic cryptid sightings.

A formerly glacier-tipped volcano that inspired none other than Jules Verne.