A haunting deserted hotel is a favorite with artists and photographers.

Time stands still at this serene burial ground in the center of Budapest.

These old World War II fortifications have been transformed into an unusual equine attraction.

A secluded art gallery hidden within the cellars beneath Tallinn’s medieval monastery.

This 1967 experiment in modular architecture was designed to be a new model for urban living.

A curious little museum dedicated to the furry feline in the cat haven that is Old Town Kotor.

This abandoned Brutalist treehouse is a hidden architectural relic.

This cubist Vienna church building looks like some sort of alien stonehenge.

What if all public housing projects had been designed by "the Pygmalion of modern architecture," not only their prototype?

Avant garde house of Pierre Cardin on the Cote d’Azur.

One architect's organic, human-centric design has been fully realized in this alien art house.

A collection of weird and wonderful art fills a former houseplant nursery.

A unique hotel for the artistic soul.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

A pair of connected skyscrapers form this symbolic gateway.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

This Parisian café sticks almost exclusively to an ethos of reuse.

Art and a pun, all in one.

Started as a kitchen garden, now the second largest botanical garden in the world.

An eerie, derelict amusement park in Berlin.

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.

Crosses of all shapes, sizes and colors litter the mountain, the site of a huge yearly Orthodox pilgrimage.

The world’s narrowest house makes for an awkward, four-foot-wide living space.