The abandoned ruins of a beautiful medieval castle just outside Barcelona.

There's a labyrinth of medieval chambers hidden deep below a 15th-century pub.

This fairytale-like structure is the last turf church ever constructed in Iceland.

A science fiction-inspired apartment building designed by a famous Spanish architect.

Mysterious chains and iron stakes adorn this strange grave, with no explanation.

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.

A fairytale island floats in the middle of Italy's little-known Lake Orta.

A tiny island is connected to the mainland by a private railway that residents travel in their own personal wagons.

An ancient Viking village in North America that predates Columbus by 500 years.

The final resting place for the remains of 143 Habsburg royalty.

There's an exclusive Beefeaters pub hidden in the Tower of London.

A meandering boardwalk across the bogland leads to a "stairway to heaven" with sublime views.

This sublime architectural marvel is a rare example of an expressionist church.

The ruins of an abandoned crematorium haunt an eerie deserted German cemetery.

A statue honors the local legend that the devil helped build St. Mary's church after being tricked into thinking it was going to be a wine bar.

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

This museum tells the story of lake dwellers from 4000 BC to 850 BC, replete with stilt houses and goats.

An elegant chandelier hangs over this ancient sewer chamber, now open for concerts and public tours.

The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

The history of German architecture is explored across this fairy-scale mini-city.

Striking occult iconography on a medieval German church.

This ancient ruined monastery has been destroyed by fire so many times that it seems like God hates it.

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

The footprint of a frustrated devil in Munich's Cathedral.