The roofless ruins of a church surrounded by acres of bucolic farmland.

Secluded amid upstate New York’s Adirondack Mountains lies this subterranean emblem of a nation on the brink of nuclear war. And it's for sale.

Historic seaside park featuring explorable, abandoned military structures.

A crumbling cliffside ruin hidden in the woods.

One artist's yard is full of shining, whirling kinetic sculptures that look like pure steel psychedelia.

This hauntingly stark structure is a relic of an industrial past.

Defying all odds, this lonely little tree found a home on a log sticking out of a Canadian lake.

This family mausoleum is steeped in symbolism and looks more like a fantasy location than a grave.

The island of Lanai in Hawai'i is a paradise for cats and cat lovers.

Doris Duke's lasting collection of Islamic Art, hidden in a Hawaiian paradise.

An abandoned bell tower in the middle of nowhere is the last testimony of a forgotten medieval village.

Buddha and Jesus tower over this French mountainside headquarters of the Aumism religious cult.

This miniature take on the Kremlin is one Dutch man's retirement project.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

The ruins of a medieval castle that once belonged to one of the most powerful families in the Netherlands.

This abandoned Brutalist treehouse is a hidden architectural relic.

The glowing blue Nymphaeum of Emperor Tiberius.

A narrow opening between the mountains of the Amalfi Coast creates a scenic hidden beach.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

World's largest herd of white deer populate a former U.S. Army depot.

Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.

A pig barn converted into one of the most eclectic residences in Nantucket.

Ruins of an old water tower that look like a horror-film castle.

This semi-spooky remnant of an abandoned hotel provides fantastic views.