In the middle of a suburban Denver neighborhood is a cave that once provided solace for a prominent Ute chief and his family.

One small town in the Pacific Northwest transformed itself into a Bavarian-themed tourist destination.

Tucked away on an empty wooded lot in suburban Oklahoma City lie the remnants of an abandoned circus camp.

A tunnel with windows, so you don't miss out on the impressive views.

A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

Erosion and time have created a naturally-formed water park.

Lines from a walking song are etched into a rock in Natural Bridge State Park.

Is this the most Portland place ever?

An optical illusion found amid a logged redwood forest.

All of the 20 occupied houses in this mostly abandoned town feature some curious display of junk art.

One of the American Southwest's most extensive collections of Navajo rock art.

This eclectic Austin curiosity shop is home to all things strange and unusual.

The oldest farmer's market in America is so ancient it was approved by the King of England.

Healing Springs that once ran red with soldiers' blood.

This Boeing KC-97 tanker is now a restaurant for aviation lovers.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

This modern castle sat empty for decades before a fire inspired its builders to complete its luxury halls.

The first custom-designed building to showcase the works of Dale Chihuly is a wonderland of glass and light.

Gleaming self-built castle towers made from beer cans and inspired by "Vitamin Mary Jane."

An architecturally-focused antique shop.

This eclectic, mosaic-clad home includes a bamboo ping-pong loft and a "Whispermaphones" intercom.

An experimental, automotive replica of Stonehenge.

In this small Phoenix taxidermy emporium, you can find everything from a squid in a jar to a freeze-dried toad.