The M in Platteville is something I've been climbing since I was a little kid growing up in Wisconsin. It's 266 steps to the top and worth the climb to look out over Platteville. The M was the creation of students of the former Wisconsin Mining School, now known as the University of Wisconsin -Platteville.
It's just a few minutes from Highway 151 and a great stop to stretch your legs on the drive as you're driving from Iowa to Madison or Wisconsin Dells. You can make a loop on your way back to 151, stopping at the First Capitol Historic Site and Belmont Mound State Park, if you have extra time.