Park 399 is one of the Illinois parks in thicket's catalog. thicket is a field guide to the parks near you: it maps the ones you have never noticed, gives you a reason to actually go, and keeps a record of where you have been.
Where it is
Park 399 is in Cook County, Illinois. Its approximate coordinates are 41.90729, -87.68872.
Check in at Park 399
thicket verifies you are actually here by GPS when you check in, so a visit means you went. Checking in builds a streak, earns achievements, and fills in your map of the places you have been.