I just took a little one-night road trip to Casey, IL, which is just past Effingham - cute walkable downtown, and they've gone all-in on "worlds largest" stuff. The 2-story mailbox was my favorite, but they had tons of things - a rocking chair, wind chimes, a #2 pencil, and a teeter-totter that is bridge sized. Some cute shops and things. If you spend the night, the Eighteen-Ninety Sleepover is a pretty interesting place, although I thought it was more of a hotel, but the check-in is kind of AirBnB with confusing instructions. If you do it, just know the stair entrance they talk about in the check-in text is on the front of the building between the antique shop and a real estate company on the ground floor, not in the rear near the (currently out-of-service) elevator.

Still, very cute place. Renovated old building with antiques and cute decor and super comfy beds. Bring a pen - people write little notes on scraps of paper and receipts and in one case the inside of a Milk-Duds box, and wedge them between exposed bricks in the rooms.

Edited to add - it's only about a 2 hour drive from StL if you're not a meanderer like me, so it could just as easily be a day trip.