[4] 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).

[5][6] The entrance to Swildon's Hole is now a small triangular opening contained within a stone blockhouse in a clump of trees 550 metres (1,804 ft) north-east of Manor Farm, Priddy.

These resulted in very different types of passageway, with the phreatic tubes, since abandoned by much of the water, forming an undulating route, much of which is known as the ‘short round trip’.

[5] The connection between Swildon's Hole and Priddy Green Sink was the first major through route discovered on the Mendip Hills.

Following a number of months of digging and blasting, the link was made in 1996 at the top of the Cowsh Avens Series, a 120 metres (394 ft) climb above Sump 4.

This was first demonstrated (by pouring dye into the water) by Graham Balcombe and Jack Sheppard of the Cave Diving Group, who first passed Sumps 1 and 2 in the 1930s.