North Hush, Gunnerside Gill

North Hush, Gunnerside Gill, Swaledale in the Yorkshire Dales, North Yorkshire.
Gunnerside Gill is criss-crossed by a series of large lead-bearing seams which have been mined since at least the 15th century. Early miners developed the process of hushing to expose these veins of lead. To create a hush, a dam was built at the top of an area to be cleared. When sufficient rainwater had collected behind the dam, it was broken, sending the water gushing down the hillside, scouring away the soil and revealing seams of lead which could then be easily worked from the surface. When the gill had been fully hushed, means of horizontal tunnelling had to be developed to gain access to the deeper veins.