Tower Hill is the park's signature dune, and climbing it is the thing most people come here specifically to do. The ascent is harder than it looks from the bottom: the sand shifts underfoot with every step, so you gain less ground than you expect and your legs burn faster than they would on a firm trail. Most people stop halfway up at least once. That said, virtually everyone who starts it finishes it, and the view from the top — Lake Michigan spreading west, the forested dune ridges rolling east — is genuinely worth the effort.
Coming down is the other half of the experience. Running full speed down a steep sand slope is one of those things that feels reckless and is actually mostly harmless, which is why it has been a rite of passage here for decades. The slope is forgiving in a way that a rocky hillside is not. Children figure this out immediately; adults usually need a moment. Either way, most people end up at the bottom laughing and covered in sand. There is no charge beyond the standard park entry fee to climb the dune.