Blanchard Springs Caverns is a large, beautiful cave in Ozark National Forest near Mountain View, Arkansas. The cave was formed by the filtering of water through the limestone rock over millions of years (a process which still continues today) and the result are some truly stunning and unique stalactites and other formations. One word of advice, though: the interior of the cave is chilly and damp so make sure to bring a light jacket of a sweater if you want to really explore it.
The best way to experience the cave is with a tour...the guides are members of the National Park System and give you information about the history and geologic process involved in the Blanchard Springs Caverns. There are two main routes: one short and sweet, the other a bit longer and more involved. The first is the Dripstone Trail; this tour takes about an hour and is perfect if you're going with kids. It take place along a walkway and there are some places to sit down if you're feeling a bit tired. The longer tour is called the Discovery Trail and it takes a little under two hours. This trail takes you a lot deeper into the caves but involves a lot of stairs, so make sure you're in good shape as well as bundled up.
Both tours cost around $10 and there are discounts for children under fifteen years old. It's open year-round but you should go in summer. The chance to spend an hour or two in a cool, 60-degree environment in the middle of the Arkansas summer is priceless!