The massive, original Colgate Clock is mounted on a defunct factory building that was once a prison.

A chapel built by Italian POWs during World War II tells a forgotten tale of the war on the home front.

You thought Santa Claus didn't exist, but it turns out you were wrong.

The farm where one of America's greatest leaders was raised is now a well-appointed landmark.

A turn-of-the-century architectural marvel built on healing mineral springs and salt licks.

"the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well . . . The pure Walden water is mingled with the sacred water of the Ganges."

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The world's longest known cave system.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

A beautiful geyser under environmental threat.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A giant Troll lurks under one of Seattle's oldest bridges.

The first declared National Monument in the United States.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

A walk through the historic city center, under the streets of Seattle.

An emerald-green grotto just a short trip from Austin.

This historic hotel invented the chocolate brownie.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

These pretty kitties killed and ate as many as 135 railway workers.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.