A battle between nature and architecture in the Cambodian jungle.

The name of this ancient Indonesian temple translates as "Elephant Cave" but it could be more accurately called "The Hellmouth."

The world's oldest bookshop still in operation.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Numerous impressive carvings are embedded in the trees lining this street in Marrakech.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

A true roadside icon standing on the same plains that the herds once roamed.

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

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

The celebrated eyesore created by starry-eyed sweethearts.

This modern museum of Mediterranean culture is surrounded by a surreal concrete honeycomb.

Hundreds of hidden passageways weave through the old quarters of Lyon.

This lovely, if imposing, piece of Canadian gothic is possibly the most photographed hotel in the world.

This trio of Dominican cave lakes comprise a colorful biosphere of natural life.

A crumbling cathedral condemned by an earthquake.

Every equinox this Maya pyramid puts on a spooky ancient light show.

A painting in the historic Cathedral Basilica depicts Jesus and his disciples dining on a traditional Peruvian menu.

Huge stone depressions which may have acted as an Incan agricultural experiment.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

The Uros people live on floating reed islands in lake Titicaca.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.