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

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

Left untouched since a double murder-suicide in the 1960s, Los Feliz murder mansion remains a neighborhood mystery.

World-famous, Pink's still manages to keep its prized cult fetish status.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

A self-built castle made by a mysterious man.

This modern antique shop is a museum for 1980's Saturday morning cartoon culture.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

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.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

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

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

A castle that was built stone by stone by an eccentric journalist.