You're looking for a camoed pill bottle. Bring your own pencil.
This is located along the McKinley Park bike/hike trail that runs through the park and out north of town toward Green Valley State Park. If you don't feel like hiking or biking that much, just look for a geocache or two and play on the playground equipment. Swings can be relaxing. Restrooms are nearby, if they are not locked. Otherwise, you may have to RETAIN some water.