A dangerous narrow-gauge railroad once traced a route through this striking canyon.

Despite his legacy of work in Spain, Cuba, and Florida, the larger-than-life writer's grave is a simple affair tucked in an Idaho cemetery.

This highest peak in Idaho can only be reached by traversing a formation known as "Chicken-Out Ridge."

These century-old beehive-shaped kilns were built to produce charcoal for nearby mines.

The world's first nuclear power plant is open to visitors looking to role-play a meltdown.

This set of hot springs also comes with fantastic views.

A former gold rush boomtown has managed to stay in business for over 100 ramshackle years.

An impressive waterfall nestled in the cliffs of Idaho's Snake River Canyon.

These falls, sometimes called the "Niagara of the West," still put on a good show at the right time of year.

Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

Smooth basaltic rocks tell a tale of ancient glacial waterfalls.

A plaque and memorabilia collection mark where A&W got its start.

California's longest-running tourist attraction is a stump.

These millipedes glow not out of attraction, but as a not-too-subtle warning.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

Where the writer penned his famous story about a jumping frog.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Eons old volcanic activity created one of the most stunning rock formations in the United States.

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

This large chunk of dark rock is a relic from an ancient volcanic eruption.

Deep vertical fissures like miniature slot canyons cut across the cemented volcanic rock of Black Point above Mono Lake.

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

A volcanic cone that formed over 600 years ago.

A natural dome made of volcanic glass in Inyo National Forest.