This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

The once highest point in China blends symbolic design with a kick of adrenaline.

This massive water spout has been luring visitors for hundreds of years, some to their death.

Bronze statues honor the brave explorers who passed through this Antarctic gateway.

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

Every week, a festive public jam session breaks out in downtown Asheville.

This North Carolina museum is keeping the pinball craze alive, with a little Space Invaders on the side.

A much more welcome kind of snowbird vacationer, manatees camp out in these springs every winter.

North Central Florida's largest flea market and a weekend roadtripper's dream.

A trek through the solar system here on earth.

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

Few things look more out of place than the electric blue ponds in the reddish-brown desert of Utah.

It's safe—and permitted—to walk across these twin natural sandstone arches.

The fifth-longest natural arch in the world, and the longest outside China.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The king of U.S. high points towers over every other peak on the continent.

This frozen tunnel in central Alaska is both an engineering feat and a valuable climate classroom.

This gravelly, dangerous highway is the only road in the United States that leads to the Arctic Ocean.

The stickered marker pinpoints where the only maintained road in the United States crosses into the polar region.

The northernmost truck stop in the United States.

The “American Gothic" artist's largest works hang in an Iowa State University library.

Beating out all other concrete competitors, this massive garden feature's pointy hat has earned it a world record.

The Binghamton area is home to six of the last remaining hand-carved vintage carousels.