The only geyser in the state of Pennsylvania is caused by pressure from an abandoned coal mine outside of the ghost town Centralia.

An underground blaze turned this village into a ghost town.

A toxic ghost town sitting atop a massive coal fire.

Narrow gorges and deep pools created by long-ago glaciers.

Since the 1930s, this Pennsylvania town has celebrated the humble tomato.

The wooden octagon in which Huckleberry Finn and A Connecticut Yankee were born can still be visited in upstate New York.

Dedicated to the art and science of glass in equal measure, this space is as much laboratory as museum.

In the mid-19th century, an eight-sided house was the latest fad.

The final resting place for the famed creator and narrator of "The Twilight Zone."

These expertly crafted, scientifically accurate glass sea creatures were once an international phenomenon.

Pluto is still considered a planet in Ithaca, New York.

This art center is way beyond your average pumpkin-carving operation.

The library of every book lover's dreams.

A museum dedicated to the legacy of Bob Moog and his pioneering synthesizers.

A wonderful display of arts and crafts handmade by local artisans in the Southern Appalachians.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

This rare basilica nestled right in downtown Asheville is an architectural marvel, inside and out.

Who needs fancy modern water slides when this giant North Carolina rock works just as well?

This granite rock face is named for the magnificent reflection that occurs when the sun hits it just right.

Gnarled canopies of pink and purple wildflowers arch over the trail to the summit.

A mountaintop space observatory that is certified dark.

This giant iron playfully pays tribute to an early 20th-century architectural trend.

12,000 sq. ft. museum tracing erotic art from antiquity to modern times.

Neglected resting place of some of the city's early luminaries—and a woman encased in concrete.