Indiana Dunes National Park

The Dunes, which became the USA's 61st national park in 2019, stretch along 15 miles of Lake Michigan shoreline. Swimming is allowed anywhere along the shore. A short walk away from the beaches, several hiking paths crisscross the dunes and woodlands. The best are the Bailly-Chellberg Trail (2.5 miles) that winds by a still-operating 1870s farm, and the Heron Rookery Trail (2 miles), where blue herons flock (though there's no actual rookery) and native wildflowers bloom.

Oddly, all this natural bounty lies smack-dab next to smoke-belching factories, which you’ll also see at various vantage points, but it's not without its superlatives: it boasts 1100 native species of plants and dunes, formed after melted glaciers, which top out at 192ft. If you're wondering what to do in the Hoosier state, this is its most visited site, attracting some 3.5 million visitors per year.