A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

Mirrors and glass shards cover every inch of this arrestingly beautiful mosque.

Iran's colorful terraces are a rare geological masterpiece.

The palace of the King of Kings, burned by Alexander the Great.

A cooled lava flow from the Haleakalā volcano formed these surreal-looking columnar basalt structures.

A hidden tunnel leads to an abandoned slate quarry that's now a secret swimming spot guarded by cliffs.

Abandoned ship reimagined as a street art canvas.

The decaying ruins of Wales' first asylum for the mentally ill.

Neolithic burial chambers hidden beside a village school.

A holy well believed to have healing powers.

A turn-of-the-century prophecy comes true when a mischievous wooden Devil watches the neighboring church burn to the ground

A little-known castle set in a nature reserve.

Following years of secrecy, the hidden history of a World War II site is being brought to light.

These precariously placed ruins harken back to a 13th-century castle.

The painting on an aptly named street honors the 1980s slasher movie.

The worst flood disaster in Welsh history might have been a lot worse if it had not happened on movie night.

Britain's only artificial surfing lake is nestled in the beautiful mountains of Wales.

This ancient castle has been abandoned since the Edwardian conquest of Wales.

A Neolithic tomb hidden among a spectacular boulder-strewn stretch of coast.

This pedestrian walkway cuts through a cemetery and over several burial vaults.

An abandoned quarrying village turned commune is now a hub for learning the Welsh language.

A Welsh sheep farm provides daily (non-sheep) meals to red kites, producing dazzling displays of aerial acrobatics.

Led Zeppelin wrote some of their most iconic songs at this little 18th-century Welsh cottage.

The largest of only eight working transporter bridges left in the world.