Caves of the Mendip Hills traverse from one cave to another through the underground rivers led to the development of cave diving; the first cave dive attempt in Britain took place at Swildon's Hole in 1934. The first successful cave dive in Britain was achieved the following year at Wookey Hole Caves, where the last sump is currently the deepest in Britain at . The cave complexes at St. Dunstan's Well Catchment, Thrupe Lane Swallet, Lamb Leer and Priddy Caves have been identified as geological Site of Special Scientific Interest. There are also caves within the Cheddar Complex SSSI. A selection of the better known
Somerton, Somerset west and then north through the Somerton Moor and then into King's Sedgemoor Drain on the Somerset Levels eventually joining the River Parrett near Bridgwater. The town is from London, south from Bristol and north-west from Yeovil, just off the Dorset border. Somerton's hamlets include Etsome, Hurcot, Lower Somerton, Littleton and Midney. Great Breach Wood is a biological Site of Special Scientific Interest (SSSI) and is situated just north-east from Somerton, near the hamlet of Littleton. Somerton's climate is typical of the climate of south-west England which is usually cool winters with warmer summers and precipitation all year round, with