This enormous abandoned prison was once dubbed the "Bastille of Romania."

A wonderfully strange collection of 500+ stuffed frogs doing people things.

The only remaining Cold War–era Minuteman II missile control center in Missouri.

The oldest bar in Missouri is hidden within a limestone brewery cellar more than 50 feet underground.

An abandoned concrete jungle surrounded by a lush park.

Famous church recognized for both its unique design and disciplined monks that live according to the Benedictine discipline.

This wooded grove of beautiful hand-built stone grottos is a hidden gem within a shuttered Franciscan monastery.

A remarkably opulent mansion with a tragic history.

If there's another drive-through golf-cart bar in a bat-filled cave on top of a mountain, we don't know about it.

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.

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

A late sculptor's last project was to turn this abandoned cement factory into a castle-themed amusement park.