One of the world's premier laboratories for hydraulic engineering research takes full advantage of the water's power.

A saintly relic hidden in a Prague church basement.

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

Walk through Czech history in Prague's largest graveyard.

A Jenga-style cylindrical tower of books that appears to go on forever.

Two stunning 17th-century libraries and a cabinet of curiosities.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

An eclectic collection of thousands of items owned by the sculptor Frederic Marès.

For one day every month Barcelona's Estació de França transforms into a market for model trains.

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

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

This Funeral Hearse Museum represents the finest in cadaver transportation.

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

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

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

This cemetery features modernist statues as strange as its name.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

A mountain path passes by several sprawling enclosures home to a pair of rescued brown bears.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

One of seven Jewish catacombs in Rome and one of only two open to the public.