Amnicon State Park is a small but scenic park, known for its many small waterfalls, rare cedar forests, and covered bridge. It's a great place for a picnic or an afternoon of hiking.
Amnicon Falls State Park, as its name suggests, has a waterfall as its central feature. Amnicon is a small and developed park and the biggest attraction is the covered bridge connecting the main park to a small river island.
Do the main loop trail beginning at the covered bridge. You'll be rewarded with great views of the cascades and craggy banks as well as open pine and cedar forests and unidentifiable ruins. This is what I would describe as a picnic park - go bring a lunch, hike a bit, play in the water if the river isn't too high, and don't feel the need to stay more than an hour or two. The highlights are worth visiting, but can be seen in a very short time.