Just when we think that we know everything there is to know about Illinois, we come across facts that surprise us. From our wide-ranging history to the interesting things happening here today, there are so many things that make Illinois truly unique. Here are some of the things that you can only find in the Prairie State:

1. The only museum in North America dedicated to surgery

The International Museum of Surgical Science in Chicago is truly one of a kind. If you've ever been curious about how we got to where we are today on the operating table, this is the place to go. This museum is one of the most unique attractions in Illinois.

2. Both black and white squirrels

Illinois is the only state where white and black squirrels both reside. To see the white ones, head over to Olney, and to see black squirrels, take a trip to the Quad Cities area. Life in Illinois sure is different!

3. The only post office you can drive under

The former Chicago Post Office allows thousands of cars to drive beneath it each day as it straddles Interstate 290. The building has been converted to office space, so the tenants have a mesmerizing distraction: Chicago rush hour traffic.

4. The world's only Popeye Museum

The beloved animated sailor was created based on a man from Chester, Illinois. So, the town has honored Popeye with a museum and shop featuring all of the memorabilia you could ever want.

5. The World's Largest Wind Chime

The town of Casey, Illinois has made a habit of collecting record-setting items, like the world's largest golf tee, rocking chair, pitchfork, and more. This wind chime is an impressive addition to their collection, standing 55 feet tall.

6. The only Forest Preserve Districts in the United States

The Illinois Forest Preserve District Act of 1913 was passed to protect our state's natural areas. They are units of government that exist nowhere else in the country and are distinct from all other government entities. The forests and nature are among the best parts of Illinois life.

7. The world's only Tully Monster remains

Over 300 million years ago, a water-dwelling being lived in the area that would one day be Illinois called a Tullimonstrum, also known as a Tully Monster. Scientists can't seem to agree on its classification, as it has been compared to everything from a worm to a mollusk.

Did we convince you that Illinois is more unique than you thought? Let us know in the comments. And, if you need more convincing, see 11 Places in Illinois You Thought Only Existed in Your Imagination.

Want to show off your state pride? Check out the Illinois apparel and accessories from our friends at Wear Your Roots.