A remnant of the original World Trade Center complex continues to serve as a commuter gateway.

This quarter-mile tunnel under the Bluff in Pittsburgh bends at a 45-degree angle.

One of the remaining markers of an era when Brooklyn and Flatbush were separate cities.

This controversial statue has migrated twice in its life.

One of Philadelphia's largest murals resides hidden under this bridge.

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

An Irish Memorial commemorating those who perished due to potato blight.

Alexander Hamilton’s creation caused quite a bit of controversy.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

The first American department store, and home to the largest operating musical instrument in the world.

Huge masonic hall in Philadelphia with lavishly themed rooms.

This beloved marketplace mascot poops money and grants good luck.

A former plant in one of the hubs of U.S. steelmaking has been turned into this museum celebrating the history of American industry.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

Eat like pre-Columbian Native Americans in this New Mexico restaurant within the Indian Pueblo Cultural Center.

The home of famed war correspondent Ernie Pyle is now a library and museum dedicated to his memory.

It's easy to see why this eclectic architectural wonder has been dubbed the "Spaceship House."

Albuquerque found the perfect use for tumbleweeds at Christmastime.

Gleaming self-built castle towers made from beer cans and inspired by "Vitamin Mary Jane."

The childhood home of Henry Jones Jr. is now an adventure-themed bed and breakfast.

When ecosystems collide in the arid Southwest.

Thousands of pieces of art have been carved into the rock at the site of an ancient volcanic eruption.

With over 10,000 lights, this engineering marvel lights up the city after dark.