The highest point in the state of New Hampshire, and while unlikely "the worst weather in the world," it sure seems that way to hikers.

Contrary to what one might expect, ice forms inside this small cavern during the summer and melts during the winter.

This Pennsylvania cave holds evidence of the oldest known inhabitants of North America.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

The only working large-scale tea plantation in the United States.

Twenty-eight years after this local landmark was washed ashore by hurricane Hugo, it was washed away by hurricane Irma.

Settled in 1696, abandoned after the Revolutionary War.

Charleston's historic city jail once held everyone from pirates to Civil War POWs.

Paths are maintained, but trees have taken over plots.

Once the most flame resistant building in the country, the South Carolina Historical Society building was almost burnt down in a fire.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

The final resting place of the Seminole Indian chief who fought against government occupation in Florida.

This recently rediscovered Civil War-era submarine was the first to ever sink an enemy ship.

Oldest unrestored plantation house in America that is open to the public.