The oldest orange tree in California spawned a generation of citrus farmers.

The largest self-built castle in the U.S., six decades in the making.

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

The largest source of fossilized insects anywhere.

While most of the games in this arcade take quarters, that would have been a small fortune when they were made.

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

There are eight natural springs around town, each with a slightly different taste.

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

Housed in a memorial lighthouse, this museum relays the history of surfing, beginning with the antics of royal Hawaiian teenagers.

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

Rising out of miles of farmland, these buttes are sometimes called the world's smallest mountain range.

Pillars made of 700 pieces of luggage climb to the ceiling of Sacramento Airport's baggage claim.

It is locally loved and ridiculed for literally looking like poop.

The largest permanent Monopoly board makes one of the longest games even bigger.

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

The largest dinosaur trackway in North America is tucked away among this canyon's ghosts and archaeological gems.

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.

The highest bridge in America was built for an almost unnervingly small amount of money.

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

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.