A massive volcanic plug is now a protected area that hosts a number of bird species.

A Mysterious Masonic tomb in San Luis Obispo.

A hotel and restaurant serving as the mecca of kitsch.

An alley covered with 20 years of bubble gum.

The ghostly remains of an accidental sea.

A landscape of massive spherical boulders are the main attraction in this Kansas State Park.

It's big, it's a ball, and it's made of twine—the world's largest of its kind.

The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.

The seamy, underground secrets of Portland's criminal past.

A tribute to the twin ideals of religion and patriotism, built by a Catholic priest from rocks, glass, and innumerable found items.

A strange house built only at night, with rumored mystic inspiration.

A 1920s speakeasy that had rum runners racing up and down the shores of California.

The rusting remains of the largest assembled WWII fleet on the West Coast.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Home of mutant livestock.

Self-built house and sculpture park where the creator can still be seen in a glass coffin.

A crumbling Beaux Arts monument to the Bay Area's age of rail.

Playable, historic pinball machines fill this Alameda museum.

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

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

This quirky roadside attraction dives into the many theories surrounding North America's most infamous hairy cryptid.

Home to the "Circus" trees created by Axel Erlandson.

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

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