The oldest U.S. Government building in California, and it's State Historic Landmark #1.

This stretch of beach along California's central coast is a busy highway for the largest seal in the northern hemisphere.

A massive volcanic plug is now a protected area that hosts a number of bird species.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

Labor provided by Great Depression-era programs restored these 25,000 acres in Tennessee.

Visit this playground of waterfalls, caves and sinkholes.

A failed utopian experiment for British expats in the American South is now a Victorian village frozen in time.

This former maximum-security prison is creepy, sobering, and supposedly haunted.

This hotel was used during the Manhattan Project to house official visitors.

The secret city built by the Manhattan Project.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

This 19th-century building inadvertently preserved the handprints of its builders within its walls.

Mile-long cave system near Great Smoky Mountains.

This high point in the Great Smoky Mountains is said to be home to the chief of all bears.

While knives are the main feature in this store, visitors will also find dinosaur bones and meteorites.

An idyllic mineral hot springs facility with a more-than checkered past.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

Thirteen pastel palaces in downtown Charleston add a gorgeous splash of color to the city.

Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

At this deceptively beautiful beach, nothing is what it seems.

Legend says one of the world's largest marine geysers is actually a whale that got wedged within the rocks.

A graceful natural rock formation stands astride the point where the Gulf of California meets the Pacific Ocean.

Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

Deep in the Guatemalan jungle stands an ancient pyramid that once marked the reign of a king.