Michigan City sits on Lake Michigan's southern shore, just east of the Indiana Dunes. It is a working northern Indiana city rather than a polished beach resort, but the lakefront gives it a clear reason to stop.
Washington Park is the centre of the visit: a broad beach, marina, zoo, and the long pier out to the Michigan City East Light. Inland, Barker Mansion shows the money made here in the railroad and freight-car years, while the Old Lighthouse Museum keeps the lake history close to the water.
Come in warm weather if you want the beach to carry the day. The city also works as a quieter Lake Michigan stop before or after Indiana Dunes National Park, especially if you want a real town with a pier walk instead of only dunes and parking lots.