Once decrepit and slated for demolition, now one of the longest pedestrian bridges in the world.

Mile-long cave system near Great Smoky Mountains.

Visit this playground of waterfalls, caves and sinkholes.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

The only place for a truly presidential dram.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

A layered tribute to the work of mosaicist Isaiah Zagar.

World's first "penitentiary," meant to be humane, drove men insane.

Why have you never heard of the second most popular tourist site in New York?

One of the indelible moments of the American Revolution took place at this location.

The first bell ever cast in Boston was cast by Paul Revere...and sounded terrible.

This massive tea kettle was once a promotional stunt for the Oriental Teashop.

"Mock all and sundry things, but leave the saints alone."

The massive machine creates cracking displays of indoor lightning.

These towering spires and glowing walls are carefully crafted from hundreds of thousands of icicles.

This World's Fair showpiece was built in Chicago, but shipped to Maine.

When the town wouldn't allow the fast-food behemoth to build a new restaurant, they put one inside an 1850 home.

The first bridge observation tower in the U.S. offers one of the best views of Maine.

A strange mark in the stone fence of a cemetery fabled to have been made by the Devil himself.

This Niagara Falls tourist trap is a world bright with neon and curiosities that will inspire love, hate, or a mixture of both.

Most-visited and most-photographed slot canyon in the American Southwest.