Rising 30 feet in the air atop Quarry Hill, the Old Powder House is the oldest stone building in the state of Massachusetts.

The headquarters of one of the world’s longest-running humor magazines bears a noticeable resemblance to a head wearing a Prussian helmet.

An alley way dedicated to graffiti and street art is a constantly changing street gallery.

One of the largest Marian shrines on the West Coast stands rather unexpectedly in Silicon Valley.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

An extravagant western hotel where every floor is the "ground floor."

This miniature feudal castle was built on a whim to honor a US Navy pioneer.

An ivy-covered arch bridge dedicated to Tejano music singer and legend Rosita Fernandez.

This landmark cemetery in Boston was created more than 300 years ago.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

America's oldest archaeological site or a muddled case of wishful thinking.

Famously misunderstood wonder of the ancient world

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

The world's longest known cave system.

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

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A museum dedicated to the alleged Roswell Incident.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Scale replica of China's ancient terracotta tomb warriors and Forbidden City are the side project of an eccentric millionaire.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.