This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

A display of magnificent stained glass windows is the first exhibit of its kind.

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

This historic hotel invented the chocolate brownie.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

An enormous park-like oasis, full of famous Chicagoans' graves.

A lush green oasis in the middle of Chicago.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

These elusive, isolated rodents evolved into a distinct, locally iconic subspecies.

A former department store turned into a quirky restaurant.

Arizona's first government hub is a rustic cabin now preserved as part of a historical museum.

The largest copper mine in Arizona, this enormous open pit emerges from the hills like an alien landscape.

After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

Hidden inside this Arizona fast food franchise is an in-depth exhibit on the famed WWII counterintelligence program.

This public square capitalized on a single Eagles reference to bring some life back to an Arizona town.

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

This striking public art installation is suspended above a public park, designed to gently move in the breeze.

A spiritual vortex among the red rocks in Sedona.

America's only nuclear missile silo open to the public.

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

A reproduction of earth's many biomes.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

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