In June we camped at Forestville Mystery Cave State Park down near Rochester. We absolutely loved it! So much to do and see. Some of the park highlights are spring wildflowers, horseback riding trails, hiking trails, historic Forestville tours and Mystery cave tours. Also one thing to note was a lack of mosquitos (however biting nats can be an issue). The kids loved the Mystery cave tour, and they also really enjoyed the historic Forestville tour. The photo below is of a pool inside the cave.