The only arched bridge made of stone on the entire Mississippi River.

A palatial art deco restroom.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

A marvel of Byzantine engineering under the streets of Istanbul.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Ancient serpentine sacrifice holder that has stood the test of time.

This collection of reclaimed landmines acts as both an exhibition of their deadly history and as a shelter for children affected by them.

A battle between nature and architecture in the Cambodian jungle.

5,000 skulls in memorial to those killed by the Khmer Rouge.

Khmer Rouge's high security prison.

Remnants of the most densely packed city in world history, that thrived on anarchy for 30 years.

The world's largest statue of Mao Zedong looks out over the city where he discovered Communism.

Museum with an extensive collection of Cray supercomputers and related artifacts.

The world's longest outdoor covered escalator system transports commuters through Hong Kong's hilly terrain.

Climb to the top of the world's largest seated bronze Buddha.

Venture into the hideout of one of Hong Kong's legendary pirates.