Elevated freight railway turned wildly successful urban park.

Once a ferry dock, radio transmitter, and now a new Greenpoint park.

Try not to get slimed in Tribeca.

Andy Griffith's hometown has made itself up to look like the fictional town of Mayberry.

America's post-nuclear-attack chambers of Congress.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

An office built to look like a giant basket.

The world's longest known cave system.

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

A singular collection of hand-built art deco cars are held in a building with style to match.

A store full of vintage and indie toys designed to bring out the kid in even the crustiest of adults.

One part antique store, one part curiosities hodge-podge.

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

A castle built by an eccentric medieval enthusiast in rural Ohio.

The world's largest collection of mechanical puzzles is a cornucopia of analog bafflers.

These grassy undulations on a stretch of University of Michigan campus aren't bad landscaping, they're art.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

One of the largest crucifixes in the world stands 55 feet tall in a secluded, wooded area of northern Michigan.

The body of one of the world's most famous outlaws is covered in cement and iron to prevent it from being stolen.

The largest cemetery in Louisville is the final resting place of Col. Sanders and Muhammad Ali.

The grave of the iconic Kentucky Fried Chicken mascot features a bust of the man behind the goatee.

Once adorning a New York skyscraper, these reclaimed ruins now haunt an Indiana park.

A flamboyantly decorated bridge signals diversity and fellowship at the entry to Indianapolis' Broad Ripple Village.