We drove/walked around Millenium Park today just to see what in the heck was up here. lol. We didn't stay long but got a gander. When I got home I did a little research on it.
It turns out that it's 40 acres and has a playground, 3 softball/baseball fields (two of which are lighted), an all-purpose field (for soccer, lacrosse, or just playing with your dog as one older gentleman was doing), and bathrooms.
Other than that there's not much to it. It is easy to miss when driving down Baptist Road. However it is very well kept and on this Sunday afternoon wasn't crowded at all. So if you just want that simple walk in the park without running into everyone and their uncle, you might want to take a ride over here.
It doesn't beat Schenley or South Park in terms of amenities, but it's a beautiful, clean park in its own right, hence the 4 stars.