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

This alley in downtown Chicago held the bodies of over 600 people after the fateful Iroquois Theatre fire.

Once at the center of U.S. finance, the historic Trading Room was meticulously recreated piece by piece and rebuilt in the Art Institute.

Over 1,000 pieces of one of the most niche art objects imaginable: the glass paperweight.

This museum celebrating the almighty dollar lets visitors literally stand in the shadow of a million bucks.

Years of archaeology, just chillin' by the water cooler.

An unassuming store hides relics of its former life as the jazz club that hosted some of the best black performers of the 1920s and '30s.

The site of the first couple's first kiss is commemorated by the most adorable presidential monument ever.

An actual 1957 Cadillac De Ville, encased in 15 cubic yards of concrete.

One of the largest pieces of scientific equipment ever carried on a NASA space shuttle sits in a Chicago alley.

This bronze sculpture on a former squash court marks the secret origins of the Atomic Age.

An avant garde art museum at the University of Chicago.

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

First planned industrial community in the United States.

This old steel industry company town has a tradition of parking cars on the sidewalk so people can walk in the narrow streets.

A relic of the Cold War in Chicago.

A sprawling outdoor museum filled with larger-than-life works of art.

The NBA player's elaborate former home is now a ghost of its old glory.

A small abandoned and abused cemetery that has become a magnet for ghost hunters.

The final resting place of the world's first nuclear reactor.

This tiny historic jail along Route 66 is the perfect fit for exactly one criminal and their partner-in-crime.

Meant for a railway that was never built because of the Great Chicago Fire, these piers still stand nearly 150 years after they were installed.

The remains of a Rockefeller's lush Italianate estate hidden in the underbrush on the coast of Lake Michigan.

Recognized the world over as the home of the McCallisters in the 1990 movie "Home Alone."