Devil's Den State Park is a beautiful park of woodlands, rivers, and waterfalls in the Boston Mountains area of the southwest Ozarks. The park is perhaps most famous for its pleasant lake and availability of horseback tours, something not all that common in many other Arkansas state parks. There are, of course, tons of trails for all levels so you can get a workout in the wilderness or simply enjoy the fresh air without tiring yourself out in the process.
If you're thinking of hiking in Devil's Den State Park, some the best trails are the Gorely King, Vista Point, and Butterfly hiking trails. Some of the trails also cut through the Ozark National Forest. If you'd rather explore the park on horseback, there are over 20 miles of horse trails, many of which lead up the park's ridges and offer spectacular views of the Ozarks.
Finally, if you're in Arkansas in the summertime, keep in mind that the park has a seasonal outdoor pool and a lake where you can swim. You can also rent boats to go fishing or cruising around at the marina.