The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

The magic's in the hole!

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

The "world's biggest dinosaur" once housed a creationist museum in its abdomen.

A museum dedicated to the alleged Roswell Incident.

A museum dedicated to the history and exploration of both popular music and science fiction.

The world's largest rotating world.

Explore the dark underground corridors of this graffiti-covered former military fortification.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

This hospital fell into ruins after failing to act as the advocate for the mentally ill it was designed to be.

Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.

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

The first declared National Monument in the United States.

Stroll through a wonderland of stupendous moss-covered trees.

A giant Troll lurks under one of Seattle's oldest bridges.

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

A layered tribute to the work of mosaicist Isaiah Zagar.

A hand-built folk art installation covered with messages of God's love.