A cabin completely covered in coffee mugs, where visitors are welcome to leave one of their own—if they can find an empty nail.

Where hikers on the Tecumseh Trail can exchange a dirty sock for a free geode.

This stimulating sex toy museum is sure to arouse the interest of its visitors.

A unique attraction and museum dedicated to exploring iconic roadside structures.

The shop's owner has spent decades in the desert wearing nothing but a strategically placed sock.

A huge collection of rocks, gems, and crystals.

This outdoor observatory offers stellar views and a scale model of our solar system.

This hidden fire lookout offers spectacular views of Sequoia National Park.

If you are looking for a used Russian battery, Chinese Ham Radio or other electronic oddities this Flea Market is a good place to start.

Four miles of pipelines form the model of still-functioning retro-tech efficiency.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

The fossilized remains of ancient California redwoods.

Somewhere between an art studio and a print shop, this artists storefront is a house of worship devoted to type.

This well-traveled chess park offers scenic views of the pacific and a colorful, eclectic clientele.

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

Here, visitors can swing with the waves of the Pacific Ocean.

Colorful Native American paintings are hidden within this small cavern.

A deserted hodgepodge of experimental structures designed by nearby university students.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

The world's largest outdoor organ is played weekly by one of just two civic organists in the U.S.

North America's largest accredited model railroad museum.

Where NASA's satellites and rovers phone home.

A working miniature city designed to teach kids about safety and presumably city planning.

A porcelain company's former dumping ground, completely covered in pieces of collectible ceramics.