This tiny island featuring 9th-century Viking ruins is only accessible at low tide.

For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

Mortarless walls that stretch for miles are a lovely solution for creating grazing land in the harsh terrain of the Aran Islands.

A formerly opulent Italian village is now a crumbling ghost town that no one really knows what to do with.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

Nordic giants resurrected from the sea and restored to their former greatness.

Despite being made of a seashell mortar, the crumbling remains of this historic Florida mill are still standing.

A former top secret nuclear fallout shelter now operates like a hotel stuck in the Cold War.

The shell of a medieval fortress offers commanding views of the area it once protected.

An abandoned Victorian-era amusement park is rusting away amidst luxury houses.

Walk in the footsteps of the gods and straddle two tectonic plates.

A short hike into the mountainside forest reveals a decaying 1890s town.

A peat bog in southern Sweden provides a cozy and photogenic home for junked Volvos, Saabs, and the occasional American muscle car.

This abandoned radar site is slowly being taken back by the jungle, its mission cut short by the end of the Cold War.

Snow-capped peaks, colorful waterfalls and stunning vistas on the edge of the Himalayas.

The ghostly remains of what was once the world's richest copper mine.

The old Route 66 town straddling Texas and New Mexico died along with the Main Street of America.

The highest point in Washington state is a volcano covered in glaciers.

This elegant arc of a waterfall marks a religious turning point.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A castle hand-built by a Spanish dreamer in the Australian tropical jungle.