Speak to a companion on the other side of the room loud and clear through this architectural anomaly.

Less a museum than a bizarre fantasy world created by artists and engineers.

A creepy sculpture of a decapitated head invites viewers to see St. Louis through its empty eyes.

This ceremonial mound is one of the first officially recognized Native American historical sites in North Carolina.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

In a city crazy for seashells this museum educates and amazes visitors using the wonder of cast-off exoskeletons.

Many of the murals covering this sleepy Florida town hide some sort of intentional error.

The unique collection includes bronze cast handprints of some of America's most famous astronauts.

The largest retailer of seashells in the world.

One of many gator theme parks, abandoned in the sugar fields of South Florida.

One of corporate America's best-kept secrets is also one of the most publicly displayed.

These ancient ritual mounds are our best window into the culture of the ancient Mississippians.

A bizarre roadside attraction and the first instance of miniature golf in the world.

Siberian husky that delivered a life-saving antitoxin.

Permanent exhibit reminds visitors of the Exxon Valdez.

A morbid gateway to an Alaska town prides itself on the hunting history it represents.

Buy your friend a drink or staple some cash to the wall for the next guy at the Salty Dawg Saloon.

Running under an entire mountain, the longest highway tunnel in North America is kept fresh using portal fans and jet fans.

North America's first frozen mummified remains of an ice age steppe bison, the 36,000 year-old mummy named "Blue Babe."

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

A 30-foot stack of piano keys memorializes one of the greatest keys players in jazz history.

At the center of this cemetery stands a 2,000-year-old burial mound of the Adena culture.

The world's tallest doric column is this Ohio monument to a naval victory in the War of 1812.

The largest earthwork effigy in the world.