Overgrown ruins of a turn of the century island fort that sees very few visitors.

The history of the tea trade is told in bas-relief on this historic pair of Boston doors.

These sprawling mines once served as a source of plaster and today serve as a storage facility.

Two dozen rescued bears roam (mostly) free at the largest bear ranch in the U.S.

Housed in the university planetarium, the thousand-strong collection of tiny towelettes includes a used one from the hosts of Car Talk.

The collection of ceremonial and cultural objects spans many countries and hundreds of years.

An angular maze of concrete in Grand Rapids acts both as public art and as a staircase for fish traveling upstream.

A Museum Dedicated to the Heroes That Fight Fire.

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

The "World's Largest Underground Business Complex," a 55,000,000-square-foot city underneath Missouri.

Community bookshelf of 25-foot-tall book spines.

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

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

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

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

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

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

Inspiring Earthlings to Boldly Go.

The hundreds of movies and television shows shot in this high desert town are commemorated in a unique museum.

Location of the most powerful laser in the world, and the potential birthplace of tiny stars.

Authentic gondola hanging from the ceiling, notable mural in the back room.

A fence constructed completely of skis on Monroe Street.