Wind Cave Boxwork--Unique

Our main outing today was to Wind Cave National Park (north of Hot Springs South Dakota). Its main feature is called boxwork, and the cave contains nearly all the boxwork in the world. It is utterly fascinating, and we had a wonderful visit. The website's home page is here.

Other distinctions of the cave are a) that it is incredibly complex, containing 138 miles of known tunnels (all under one square mile on the surface)--making it the 5th largest cave in the world, and b) that barometric pressure produces winds into and out of the cave--it was discovered by the sounds of those winds. AND, by calculations from those pressure, geologists have calculated that the known tunnels in fact represent only about 5 per cent of those that exist--explorations are ongoing!