Swildon's Hole is an extensive cave in Priddy, Somerset. At in length, it is the longest cave on the Mendip Hills. It has been found to be connected to Priddy Green Sink and forms part of the Priddy Caves Site of Special Scientific Interest (SSSI). The upper series of the cave compresses many features into a relatively short space. The cave goes far beyond this, however, and the lower reaches of the cave continue to provide challenges for even the most experienced of cave divers. The name may be a corruption of Swithun, an Anglo-Saxon bishop of Winchester, as the land in the area was owned by St Swithin's Priory in Winchester. History The cave was first entered on 16 August 1901 by members of the Wells Natural History and Archaeological Society. Very rapid progression was made to what is now known as the 40 foot pot. Between 1903 and 1910, in spite of access being banned by the landowner, various trips took place to photograph and explore the passages. In 1914 the limit of exploration was extended to Twenty Foot Pot, and in 1921 the first of the sumps was reached, but not passed (despite attempts to make progress by blasting). Sump 1 was finally successfully dived in 1936, and Sump 2 was passed soon afterwards. By this point a length of cave only one-fifth of the amount known today had been discovered. Ever since 1936 caving groups have been seeking to extend the explored area of the cave, and thus far eleven principal sumps have been passed. Sump 12 has so far proved impassable. Work continues to find a way through the adjacent Sump 12b. Access The entrance to Swildon's Hole is now a small triangular opening contained within a stone blockhouse in a clump of trees north-east of Manor Farm, Priddy. Swildon's Hole is a very popular cave and there are often several separate groups underground at the same time. Description The cave contains an active streamway, which has caused a highly varied cave system. Areas of the system range from low passages, through which cavers must crawl, to impressive chambers with sheer drops, and from dry fossil passages to thundering waterfalls and its infamous sumps. A plaque mounted on a stone plinth near Priddy village green shows a plan of the cave, overlaying a map of the village (see right). The cave exhibits a combination of