One of the world's earliest skyscrapers.

This haunted hotel built on natural springs once served as a hospital for a quack doctor promising a cure for cancer.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

The obelisk meant to mark the founding father's grave at Monticello is actually on the University of Missouri campus.

A museum where visitors can learn about greyhounds and (more importantly) pet them.

This unconventional used book store was once in the news for the surprising act of burning books.

This quaint museum lets you take a ride on its antique carousels.

This futuristically sylvan church is a glass-enclosed marvel of modern architecture.

An acoustic anomaly with a mysterious cause.

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

Entombed in this strange, white stone hill are the deadly remains of radioactive weapons production.

Less a museum than a bizarre fantasy world created by artists and engineers.

Speak to a companion on the other side of the room loud and clear through this architectural anomaly.

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

This titanic oil company sign is a reminder of the Americana boom of the 1970s and also its commoditization.

One of few surviving standpipe water towers in the U.S.

A historic house in St. Louis was plagued by a series of suicides committed by family members involved in a successful brewery.

This mosaic-covered bar is brimming with curated curios.

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

Giant works of art interspersed throughout meadows and woodlands offer a new discovery at every turn.

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

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

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

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