One of the best and most fun museums in the country is Chicago's Museum of Science and Industry. From and actual captured WWII German U-boat, to a scale model of Chicago complete with working trains, to various aircraft dive bombing you from the cieling. A lot of interactive displays and just a great time for the whole family.
Another great spot to spend a day is at Chicago's Botanical Gardens. From beutiful flowers, green trees and grass, waterfalls, Japanese tranquility garden, and a very large model train display that takes model trains past historical sites across the country.
The chapel at Holy Hill, Wisconsin. We got there a bit late and didn't get to go inside. Very sad, but maybe next time.
We took a ton of pictures at House on the Rock in Wisconsin. A very interesting museum by all means. My favorite part was the model ships they had on display, the rest seemed to be a very eclectic collection of crap. It would benefit visitors if they would provide more information on the items they had on display, and while the giant carousel is cool in its own right, some of the "horses" and the ladies on the wall and ceiling were just plain creepy.
For good family fun, the Dells in Wisconsin is the place to go. A whole city that caters to fun. Hotel/amusement parks, jet boat tours, go cart racing. All a great time. We took a tour of the Dells via water and while getting soaked by the rain, Jacki and I couldn't help but laugh at the tour guide that did not know anything about what the boat was going past, and didn't even know her right form left. It was a joy by all means. However, the scenery was breathtaking and who doesn't like boat rides?
A quick trip down to Indiana and the Dunes on the coast of Lake Michigan. A huge playground for those looking for summertime fun on the shores of the lake with the skyline of Chicago looming in the background. A big deal is to hike to the top of Mount Baldy. At a booming 150ft, it is quite an endeavor. Actually, the hike up is a little tough as to get to the top you have to walk up hill in some pretty soft sand. It is a good workout.
Mount Baldy.
If you're in Chicago and a little short on funds, the Lincoln Park Zoo is a good place to see. Admission is free and it is not just some small zoo thrown together for you to see in an hour. It is a proper zoo and it'll take you a good portion of the day to see all of the exhibits.
And a trip to Navy Pier is always a good idea and a fun way to spend a few hours. Shops, restaurants, beer garden, and a stained glass museum are all available at Navy Peir.
Remember to tread lightly and leave no trace.
Aaron