Went there a lot as a lad myself. Big boulder field and a nature trail. Boulders have a high iron content so when you hit them with a hammer they have a bell like ring, minus the sustain. There's a box at the trail head marked "take a hammer, leave a hammer". The kids, almost 2 and almost 4 years old did incredibly well navigating the terrain. Are there other parks with niche attractions like this? Not necessarily a come beat rocks with a hammer park, but something of that sort of odd. I saw that there's a ringing rocks in Montana, according to Wikipedia.