High Cliff State Park, just about 10 minutes from Appleton, is a large state park on the shores of Lake Winnebago with dolomitic limestone cliffs towering over the lake. Near the highest point is a 40-foot observation tower, shown below, that provides a beautiful view of the lake and part of the Fox Valley. The view shown below is looking toward Appleton and Menasha.

Lake Winnebago covers 215 square miles of Wisconsin and is one of the largest inland lakes in the U.S. The park also has ancient Indian effigy mounds, including several animal shapes. High Cliff Park is a great place for hiking, exploring, camping, bike riding, picnicking, and even swimming (when the water is warm and not too rich in algae). And it's a great place to find wild grapes in the fall.