Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

This Croatian fairytale castle is slowly falling apart thanks to years of neglect.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

A waterfall runs right through the middle of this Taiwanese shrine to the hundreds of workers killed while building a nearby highway.

The programmatic glory of LA's giant whiskey barrel building has become an upscale reminder of the city's kitschy roadside past.

This abandoned sea fort has become an accidental bird sanctuary.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

This semi-secret storybook hedge maze is also the oldest garden in the city.

This remote island village was in danger of depopulating completely until a tunnel was built to connect it to the rest of the world .

Hidden well off the beaten path in Catalonia is this crumbling medieval castle that is slowly being covered in graffiti.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

This luxury shopping lane has been protected by its own tiny police force for over a century.

This dramatic rail curve was once the target of a failed Nazi attack.

Don't be a grizzly man. Get personal with Alaska's wild bears from the safety of this conservationist camp.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

The remains of a Canadian train crash are now mouldering beneath layers of rust and graffiti.

This haunting stone chasm is a hotbed of mossy rock and English legend.

This medieval Italian town is a sheer (and beautiful) cliffside defense.

This ancient Irish tower could easily have stood in for Rapunzel's prison.

The moving metal works of one troubled artist can still be viewed on his front lawn... for now.

This ancient abandoned church in a remote part of Turkey is in danger of falling over.

This ancient burial mound is accessed by an impressive Greek-built archway.