Where thousands of slaves passed through the "Door of No Return."

This series of rope-style bridges brings visitors into a jungle layer that is usually reserved for birds and monkeys.

The dead gigantic radio tower of Liberia.

Empty since 1989, now falling into ruin.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

One of few remaining antique carousels with stationary animals in the U.S.

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

The first declared National Monument in the United States.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

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

The same security that protects our nukes accidentally protected a gentle herd of antelope.

Site of the 1879 Cheyenne Outbreak and the site where famed Sioux chief Crazy Horse met his fate.

An experimental, automotive replica of Stonehenge.

This erect, phallic geological spire wasn't always named so domestically.

Quirky water tower advertises the long-gone Brooks Tomato Products Co.

The fairy tale castle of the "fairy-tale king."

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

The hometown of Popeye's creator is littered with a growing collection of granite cartoon characters.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

Man-made geyser that rises to the exact height of the Gateway Arch.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

What was once a presidential estate is now an exotic menagerie and home to the Budweiser Clydesdales.

The Magic House provides a beautiful and creative environment for curious youngsters to get their knowledge on.