This is one really big nut.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

The site of Billy the Kid’s most famous escape and the end to the Lincoln County War.

The final resting place of the living embodiment of the famous Forest Service symbol.

More than 21,000 images fill this overlooked gem of a prehistoric site.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

This quirky hot springs town known to locals as "T or C" was named after a radio show.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

Ancient pueblos built into the base of a natural canyon wall.

An important piece of history from mankind's journey to the moon sits in the lobby of a government science lab.

Witnessing the might of this dessert-colored desert waterfall is a rare, powerful treat.

An artificial crater field that trained astronauts for lunar exploration.

The eroded core of an ancient volcano is now accessible by a short hike.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Most-visited and most-photographed slot canyon in the American Southwest.

Rippling sand dunes frozen in the Arizona rock.

Giant pinnacles in the sun-scorched lands of Southern Utah have been nicknamed "white ghosts."

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A striking, menacing sandstone peak towering above a landscape that's equal parts Mordor and the Moon.