A 90-foot-tall psychedelic "tree" on the side of the highway has baffled passersby for decades.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

Surrounded by a hundred mile radius of billboards, Little America is a roadside attraction whose primary appeal is hospitality.

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

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

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

A downtown park built on top of unclaimed graves.

An annual festival celebrating Colorado's most famous frozen corpse.

The final resting place of American icon Buffalo Bill, and a museum that aids in telling his tale.

Every equinox this Maya pyramid puts on a spooky ancient light show.

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

Where the polar bear watches over everything, and every drink is a double.

A store that sells all manner of bones, insects, and animal curiosities.

Oakland's beautiful monumental cemetery.

An "anarchical" no man's land, complete with garbage sculptures and a hobo-run "Landfillian Library."

A 90-acre park on former landfill that hosts an annual kite festival.

An vast warehouse of everyday treasures in Berkeley, CA.

Dive bar built out of the remains of a whaling ship.

An enormous illuminated figure dances on the Las Vegas strip.

A man-made island in scenic San Francisco Bay.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.