This innocuous New Mexico storefront was once the secret jump-off spot for Manhattan Project scientists.

The oldest continuously occupied public building in the United States.

This giant pocket watch is the third iteration of a local landmark that has been standing just off the Santa Fe Plaza for over 100 years.

This southwest-styled home in Santa Fe claims to be the oldest house in America thanks to an ancient bit of foundation.

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

Conflicting markers on its floor tell a tale of two city centers in San Antonio.

The iconic Chicago sculpture hides a beautiful and easily overlooked plaque on the backside.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

A monument to the art of slicing people open.

A Bibliophile's Dream.

This shop for all your super spy needs hides an educational secret.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

This opulent 16th-century Maharaja’s palace is a unique mix of Hindu and Muslim designs.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.

The world's second-largest sundial, made entirely out of stone.

The 953 windows undoubtedly make this the world's most beautiful screened porch.

An ancient iron pillar in Delhi that seems to be rustproof.

Inside the Wayne County airport is an amazing collection of lights and sounds.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

The plants form a living library and laboratory for researchers and students at Michigan State University.

A horse-drawn 1858 steam pumper fire engine encased in glass on the front lawn of a Michigan insurance company.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

An angular maze of concrete in Grand Rapids acts both as public art and as a staircase for fish traveling upstream.