Water Works Park has a natural playscape with a swing, a sand play area and many places to climb. It's next to Lauridsen Amphitheater, so be sure to check for events before visiting because there was no access to the playscape during a recent concert I attended. Also nearby is the
Des Moines Biergarten, which is fun to visit and family friendly. There are modern restrooms near the playscape, which are open year-round.
