A herd of 150 bison live on California's Santa Catalina Island and are at the heart of an ongoing debate between environmental protection and economic expansion.

Special tunnels built so that frogs won't be killed when crossing the highway.

From Japan to Italy, this California park explores the world's cultures through their gardens.

An historic and oft-filmed spot for musclebound iron pumpers on the Pacific coast.

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

The largest man-made crater in the U.S. marks the spot where we once tested mining with nukes.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

The farthest you can be in the contiguous U.S. from a McDonald's location.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

A gothic palace of endless stalagmites and pseudoscorpions waits within one of the world's most beautiful caves.

A chance to sleep among the firs and pines of the Oregon forest.

A surreal landscape where fanged rocks rise from the ground and the ocean feels like a great mystery.

A tiny red pebble marks what may be the quietest outdoor spot in the United States.

A hiking area billed as a possible home to Bigfoot.

Railways may have forged this quintet of lovely tunnels, but now they are open to hikers.

One of the largest collections of wildlife art in the United States, built into the side of a cliff in rural Wyoming.

A little piece of the Shire is hidden behind a plant nursery in Port Orchard, Washington.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.