Unfolding along the western edge of Sturgeon Bay  and flanked by Sherwood and Cabot Points, Potawatomi State Park (920/746-2890) is known for rolling birch-lined trails atop the limestone ridges scraped off the Niagara Escarpment. The geology of the park is significant enough that Potawatomi marks the beginning of the Ice Age National Scenic Trail. You won’t need a science background or superlative designations to appreciate its inspiring vistas and solitude; it is, simply, one of the peninsula’s magical, not-to-be-missed natural retreats.
Almost 11 miles of trails wind through the park. An eight-mile off-road bicycle trail also meanders through grassy meadows. The great Tower Trail quickly ascends the ridges through thicker vegetation, leading to a 75-foot-tall observation tower and a belvedere vantage point of Michigan’s Upper Peninsula on a good day (check out sunsets!). Islets rimmed in hues of blue and gray pepper the outlying reaches off the park (bring a polarizing camera lens on a sunny day). Fishing in the naturally protected bay is some of the best in the lower Door. The chilled waters also offer some fantastic scuba diving, with wrecks seen below.
Popular are the 14 miles of cross-country skiing trails and winter camping areas. Camping is popular as hell, so reserve the first day possible the winter before your trip; I’m not kidding. A camping cabin is available for disabled travelers. A park sticker is required in addition to the campsite fee.
For a quick road trip, head back toward WI 42/57 but turn right onto Highway C and then right onto Highway M, which takes you all the way to the Sherwood Point Lighthouse (it’s a bit tough to spot). Built in 1883, this one took precisely one century to finally become automated! The 38-foot-high house guarding the bayside entrance into Sturgeon Bay  was constructed with a 10-sided cast-iron light. Closed to the public, it and the old keeper’s house are used today as a retreat for the Coast Guard. It is also open only during designated festival times, generally late May or early June.