Arkansas is alternately referred to as The Natural State and The Diamond State. The number and beauty of its state parks explain the first nickname; a visit to Crater of Diamonds State Park explains the second. The park presents a geology lesson amped up by opportunity; the opportunity—no kidding—to search for, discover, and take home diamonds. For less than $10, you can access the search area, an eroded crater surface that yielded its first find in 1906. For a few more bucks, you can rent basic digging equipment. Park visitors are still making discoveries today.