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

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

On Japan's Tashirojima Island, cats are king.

An exquisite tunnel of cascading flowers.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

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

See massive fossils that are over 200 million years old in northeastern Arizona.

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

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

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

Dramatic river bend surrounds a natural red-rocked pedestal.

Rippling sand dunes frozen in the Arizona rock.

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

Limestone caves with spectacular showcase chambers.

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

This historic national park is covered in the stunning ruins of red rock pueblos.

A winding path built in secret on the edge of the continent.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

The world's largest carnivore sanctuary is home to over 450 meat-eating rescues.