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

Nursery with extensive collection of flesh-eating plants operated by the author of "The Savage Garden."

The haunting ruins of Jack London's dream house.

One of the oldest reform schools in the United States, home to wayward boys such as Merle Haggard, now abandoned.

An old-timey medicine shop that once served Chinese laborers during the Gold Rush is still open for business to this day.

The largest drain hole in the world.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

Seven ceramic sculptures are scattered around this California college campus.

An eccentric home stands out in an otherwise average neighborhood with mosaics, mini topiaries, and kinetic sculpture.

A tiny survivor of the Donner Party disaster.

Eclectic collection of dark and macabre antiques.

This museum looks at the history of one of America's most famous prisons and most beloved albums.

Delightful disarray of found objects and clutter.

An emporium for the weird, creepy, rare, and just plain gross.

Tens of thousands of tiny birds swarm into one school chimney every fall.

Taking the 3D art experience far beyond blue and red glasses.

Their motto is, "We've been bonkers for hats even longer than you have!"

Home to the only outdoor municipal elevator in the United States.

You might know it as the Overlook Hotel, but the inside is not going to be familiar.

The self-made house sculpture of an outsider artist who named himself "Chief Rolling Thunder."

A trash dump made beautiful by nature's power.

Bits and pieces from the ill-fated Donner Party's winter cabins.

World's largest porcine hairball sits in a collection maintained by Benedictine monks.

The modest home of the very immodest dancer who cost a king his crown.