A psychedelic labyrinth on the San Francisco bay.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

An artsy hidden staircase leads to breathtaking views of San Francisco.

An abandoned early-20th-century boomtown sits within the Calico Rock city limits.

A small canyon with petroglyphs and a seasonal waterfall, only a short hike from the remnants of old Route 66.

The lost ruins of the forgotten ferry lie hidden beneath the silt.

These free-roaming horses were once destined to disappear from the land.

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

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

The story of Two Guns, Arizona could easily be described as a Shakespearian tragedy on Route 66.

Ancestral Puebloan ruins, natural arches, and box canyons abound in this seldom-visited corner of Monument Valley Navajo Tribal Park.

A stealthy Apache hideaway that became the haunting site of a mass grave.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

A reproduction of earth's many biomes.

A self-built castle made by a mysterious man.

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

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

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.

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

Rippling sand dunes frozen in the Arizona rock.

Research missiles and rainbow auroras at the world's largest land-based rocket range.

This ghostly Alaska village still clings to a steep cliffside despite having been abandoned for over 50 years.

This WWII-era military installation once held an entire city within its walls - now, its walls are falling down.