The 7,000-year-old calcium carbonate formation creates a magnificent natural bridge.

Small and slightly hidden, the American Writers Museum is preserving the legacy of America's finest authors.

In a quiet north Chicago neighborhood rests a stunning relic of the golden age of earthenware design.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

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

These chunky stone towers out in Lake Michigan are the key to Chicago’s drinking water.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

This bird-shaped rock formation defies gravity, time, and classification.

This sundial indicates the time based on where you stand within it.

A restored 114-year-old railroad station heralded as the most photographed depot in the United States.

Detroit’s downtown castle is one of the oldest structures in the city.

The world’s largest Masonic temple was saved by the White Stripes.

A monument stands at one of the starting lines of the Trans-Canada Highway, formerly the longest uninterrupted highway in the world.

Looking strangely like Rome's Colosseum, this unfinished tower has dominated the skyline for over 100 years.

The Kalamazoo factory has 100 years of instrument-making, and one big wartime secret.

A natural formation that resembles a camel resting in the New Mexico desert.

This sparsely populated town offers a look back in time.

Some 2,000 carvings show this rare desert spring has been an oasis for travelers for over a thousand years.

A burnt-out motel with priceless Native American artwork in the basement, redeveloped into apartments.

Giant origami sculptures tucked into desert scenery beckon passers-by to explore further.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

The longest structure of its kind ever built in Michigan.

A mass grave for victims of an airline disaster that led to much-needed safety improvements for commercial flights.

Once a home for cows and hay, this barn has been transformed into an event cathedral.