An abandoned concrete jungle surrounded by a lush park.

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.

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.

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

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

A huge musical instrument played by the ocean.

One extremely determined man's homemade universe.

Meet the "Green Monster" of Monico, Wisconsin.

The Bong-area park police have asked visitors to please, stop stealing the signs.

Expansive and colorful studio of Minneapolis art-star, Doug Padilla.

A 100-year-old chair with joints "cemented by nature."

This whimsical sculpture garden is a local treasure.

A bronze plaque marks the site of the only show the "King of the Soul Singers" ever missed.

143 feet of leaping muskie whose mouth can be used as a wedding venue.

Whimsical sculptures dot a woodland path surrounding their creator's old summer cottage.

This forgotten beach house built to look like a Frank Lloyd Wright masterpiece overlooks a hidden beach.

According to the legend, this strikingly beautiful hill has miraculous healing powers.

One Austrian's singular yard is now preserved as a folk art garden of concrete wonders.

A bedazzled house and crown "jewel" of outsider artist Loy Allen Bowlin.

An oddly poignant roadside attraction celebrating American folklore.