Medieval town turned hippie commune, once home to the secret foreskin of Jesus Christ.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

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

This 16th-century monastery has been turned into a surrealist architecture compound.

An Italian hillside ghost town.

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

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

A brightly colored natural bridge formed by mineral-rich hot springs high up in the Andes.

The explorer Captain Cook may have named it White Island, but the Maori call it Te Puia o Whakaari – The Dramatic Volcano.