Small, privately owned island divided between Michigan and Ohio with abandoned vacation homes and a derelict lighthouse.

Rare recess caves fill this unbelievably beautiful Ohio park.

An abandoned asylum incorporated into a college campus.

Around 50 million gallons of water flow from this spring every day.

European castle ruins in an American state park are actually the product of death and grief.

These pink granite water slides are the result of millions of years of erosion.

A subterranean haunt where wine and homemade biscottis are always on the menu.

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

In the St. Francois Mountains in the Ozarks at 1,772 feet above sea level, Taum Sauk Mountain is the highest (and possibly oldest) peak in Missouri.