The ruins of a pre-Columbian fortress city so secure it held off the Spanish conquistadors for over 20 years.

This rustic old building is said to be the most photographed barn in America.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

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

An architect's childhood fantasy treehouse made real.

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

A beautiful geyser under environmental threat.

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

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

This elaborate towering structure was once famed for its revolutionary height.

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

Practice your Dirty Dancing lifts in the manmade lake where Johnny Castle himself did.

This former hub for crafty philosophers was founded by a writer who died aboard the infamous RMS Lusitania.

A 19th-century architectural wonder designed by the "father of the skyscraper."

The seat of Buffalo government is a gorgeous Art Deco palace.

A collection of unique outdoor sculptures surounded by the beauty of nature.

This sandstone gorge in New York State's Adirondack Mountains is home to waterfalls, flumes, and more.

A castle built for love, and abandoned due to heartbreak.

In upstate New York, gorgeous waterfalls and a watermill are slowly being reclaimed by nature.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

The only road through the heart of Glacier National Park.

This float factory takes the mask off of Mardi Gras and lets visitors see where the magic happens.

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

With 8,000 pipes this giant instrument is the most versatile theatre pipe organ ever built.