Built in 1900 by leading brewery architects George Adlam & Sons of Bristol, for Charles Westlake. At time of its opening it was acclaimed by the Brewers Journal as 'of the most substantial character in every way' and 'the plant will be of the most modern description, both scientifically and practically.' This new brewery superseded the one opened by Charles Francis Westlake in Blaenavon in the 1880s; unreliable water supply led to the move down to Cwmavon. The company, Westlake's Brewery Ltd, had been founded in 1889. By 1907 the company had a chain of pubs and in 1911 Westlake's took over the Castle Brewery in Pontypool. The business declined in 1920s and brewing at Cwmavon ceased in 1928. In 1936 the buildings were taken over by The Eastern Valley Subsistence Production Society with the objective of helping the problem of local mass unemployment. Now the former brewery has been converted to a plastics factory.

The pond is shown on the 1920 OS as a 'well'. In the hillside to the E are 2 watercourses emerging from brick-segmental-vaulted culverts. Water flows through a combined walled channel to a small pool, semi-circular in plan and of approximately 10m diameter. An overflow to the river is on the S side.

R Hayman, Hayman & Horton, 20/1/2003