Located near downtown Bentonville, it's a unique name for a unique mountain biking experience -Slaughter Pen, which offers both a single track trail and a freestyle area. Pinnacle Mountain State Park offers a wilderness float trip on the Little Maumelle, just minutes away from Little Rock. White River National Wildlife Refuge in east Arkansas at ninety miles in length, is the largest in the state. People from all over the world come to "the Crater" near Murfreesboro in search of diamonds because it's the only diamond-producing site in the world open to the public.