Sag Valley is part of the Cook county forest preserve and gives you a good idea of what the Orland Park area used to look like. The area is spotted with sloughs, like marshy ponds, and small creeks. At the beginning of the trail is a stairway that gains a little bit of elevation and you'll probably see people exercising on it. The trail itself is much less crowded and a nice walk for a nice day. Make sure you bring insect repellent because it is very buggy. Horses are also allowed on the trail so if your into that..