There's a new island on the lake at Holly Area Recreation Campground, but it's not the result of yet another underwater volcano. And the figures clambering over it aren't castaways but thrill-seekers in swimsuits. This is Jump Island, an inflatable waterpark complete with slides, bouncing surfaces, and blow-up volleyball courts.

There are just a few simple rules you need to follow to head off on your next fun-soaked adventure. First, no sharp items, so leave the dangly earrings, poky bracelets, and pet sharks at home. Second, everyone must wear a US Coast Guard–approved life jacket, and Jump Island is happy to provide them. Finally, all guests must be at least 48" tall. Most of the other rules are common sense—no rough-housing, no swimming under the park, and no head-first diving allowed.

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