The wreckage of a deadly bomber plane crash can still be found near an Arizona peak.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A once popular resort—said to be the vacation spot of gangster Al Capone—now remains abandoned in the woods of Arizona.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

Locals dubbed it the "Owl Building" because of its bird-like appearance.

On a small Puerto Rican island, banks of secret naval bunkers lie abandoned and filled with piles of office equipment.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

Rusting, graffiti-covered tanks litter the beach of this island, once used by the U.S. military for target practice.

A towering bronze statue memorializes the founding father of postwar American conservatism.

A geological mystery on Camelback Mountain.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

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

A downtown park built on top of unclaimed graves.

Once a mortuary that held the remains of Buffalo Bill, this Denver hotspot is now a death-fixated restaurant.

One of the greatest heroes of the Titanic tragedy came from humble beginnings to this beautiful home.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

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

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

See massive fossils that are over 200 million years old in northeastern Arizona.