I think I would like to try to visit all of the national park service sites within 200 miles of my house. I went to Find a Park, and found that I have five:
Effigy Mounds in Iowa
Apostle Islands in Wisconsin
Pipestone in Minnesota
Mississippi River in Minnesota*
St. Croix in Wisconsin
*barely counts because it's right here in my city, and I would not need to make a travel weekend of it. This prompts me to search again...
A search of 250 miles adds Herbert Hoover, a National Scenic Trail, Ice Age, and Grand Portage.
I like this resolution.