Cascade Falls is a waterfall in the town of Osceola, WI and is just a short drive from Interstate Park.   
It hardly can be considered a hike since you just park on the side of the street, hike down a set of stairs, and you are right there!   Was the first time I have been to a waterfall that was right in town and actually drove right by it the first time!  
It was the perfect outing for a hot June afternoon though!   There is even enough room to get underneath the falls and cool yourself off!