Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

The only road through the heart of Glacier National Park.

An architect's childhood fantasy treehouse made real.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

A beautiful geyser under environmental threat.

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

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

An Alaska livestock farm devotes itself to harvesting wool from creatures that once ran with mammoths and sabertooth tigers.

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

New Orleans' famous cemetery, located on the site of a former race track.

A building so large that it has its own weather.

A tribute to Ponce de Leon's supposed quest for eternal youth.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

Rural churches in the middle of nowhere with religious frescoes by famous artist.

Three hundred years of preserved Spanish colonial history in San Antonio.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

The second oldest continuously operating bar in Louisiana.

A health museum containing a 27’’½-foot intestine.

The LSU mascot lived on the college campus in one of the most impressive tiger habitats in the country.

What was once a presidential estate is now an exotic menagerie and home to the Budweiser Clydesdales.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

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