Mysterious 500-year-old tapestries depict a unicorn hunt.

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

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

The rocks in this arid basin leave trails of movement behind them.

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

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

Strange red rock formations that have been attributed to a higher power for hundreds of years.

A hospital closed seemingly in the middle of operations, leaving behind fodder for horror films and ghost hunters.

The world's longest known cave system.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

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

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.

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

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

Resting place of Hollywood's immortals is also site of summer film screenings.

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

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

Dramatic river bend surrounds a natural red-rocked pedestal.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

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

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.