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

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

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

The longest living non-clonal organisms on Earth.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

I-95's Tijuana-style celebration of kitsch at the Carolina border.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

The hallucinogenic center of the ancient world.

Roman ruins top white travertine terraces formed by ancient hot springs.

Ozymandias’ time-keeping temple.

The largest known Ancient Egyptian obelisk.

This famous city eluded concrete detection until the early 2000's.

The largest prehistoric ruins south of the Sahara, once a powerful center of international trade.