Indiana Dunes State Park
: 41.6623° N, 87.0394° W
An hour outside of Chicago rests a pristine pile of sand that spills into Lake Michigan through miles of trails that will surely eat away at your ankles. We came here in January before Aiden was born and instantly fell in love with it. If you're an out-of-towner it's just $12 a car for 24 hours of trail hiking, sand castle building, and rock skipping (if you're lucky enough to find a flat rock).
Can't hike 24 hours straight? Head up the road, just into Michigan, and stop by New Buffalo. A quaint tourist town with a couple great restaurants including the Stray Dog (or is it the Lost Dog?).
Plug in the coordinates and enjoy.