The show pony of cave systems, Fantastic Caverns manages to live up to its name.

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

Curious cave that stays a cool 56 degrees all year long.

The world's largest man-made underground caverns offer unparalleled underwater wonders.

The history of the treatment of mental illness, illustrated in all its gory detail, and housed in an asylum.

This abandoned prison castle has become an imposing gallery of graffiti art.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

An eclectic assortment of medieval architecture in a small Iowa town.

For just a few bucks, this Iowa funicular will let you feel like an 1800s fat cat.

A warning to the weak-kneed: This narrow bridge does its swinging eight stories high.

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

A number of gruesome unsolved murders have turned this simple home into a morbid tourist trap.

This zombie-themed restaurant stands out in the heart of corn country.

These Great Lakes sea caves accessible by boat in the summer turn into temples of ice reachable by foot in the winter.

A bizarre house filled with an astounding array of collections.

What was meant to be a temporary exhibit is now a permanent fixture at the St. Louis Zoo filled with beautiful birds.

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

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