Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A battle between nature and architecture in the Cambodian jungle.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

Monasteries on rock pillars, once accessible only by frayed ropes.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Northern Ireland's Brobdingnagian stepping stones.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

The ghostly remains of an accidental sea.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."