New fungal and bacterial species call this deadly lake home.

This historic cliffside mansion uses a natural cave for air conditioning.

A Muppet museum in small-town Mississippi honors the roots of Jim Henson's most beloved creation.

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

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

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

This iconic water tower and failed bandstand is open for panoramic views once a year.

This large midwestern cavern features impressive rock formations and an underground waterfall.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

The famed architect designed this Minnesota gas station of the future with a lookout tower.

What was once the largest NFL stadium.

This empty Detroit high school was too expensive to maintain or destroy.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

This freshwater spring fills with 10,000 gallons of water per minute.

Turnip-shaped island just off the Michigan shore in Lake Huron.

Abandoned concert venue legendary for its rock counterculture.

Easter in Westminster may be the only time and place to behold Edgar Allen Poe made entirely of Marshmallow Peeps.

Massachusetts memorial to murder victim Elizabeth Short near the spot where she was born.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

It's not a typo, now say it five times fast!

Walk through the history of American pop culture.

Dim sum, served in a grand old theater.

The land is home to swimming ponies and a legendary 18th-century treasure.