Centennial Park (open during daylight hours, and they do close the parking lot gate) has a lot to give, both in terms of geocaching and nature in the middle of the suburbs. I live across the street and try to come here every day for walks and to appreciate nature. There are already three great geocaches here, and I thought, why not add one more?
There is only one vaguely reasonable way to get to this geocache (DISCLAIMER: Some of you may end up disagreeing with my definition of "reasonable"). The park has a network of paths, and there are several ways to arrive at the one reasonable path (see waypoint). This path crosses a small stream (someone has put quite a bit of effort recently into making a bridge here). You may get wet. You may get muddy. The footing can be a bit slick on the sticks people have laid down over the watery/swampy bits. There will be some blackberries and other stickerbushes. The path may stop being a path at some point.
I'm used to bushwhacking so I'm not sure my opinion can be trusted, but I think the way is fairly easy - you should not need to go through trees or brush. Just some tall grass and side stepping of the biggest mudholes.
Bring your own pen. Container is on the large end of micro.