RCAHMW digital colour oblique photograph of Aluminium Smelting Works, Holyhead. Taken on 20/03/2005 by T.G. Driver.

Penrhos Works began producing aluminium in 1971 and has a capacity of some 126,000 tonnes per year. Alumina and coke ships berth at the jetty in Holyhead Harbour which is linked by a series of underground conveyor belts to the plant. The plant is also served by a railway siding from the adjacent north Wales main line and this is used for receipt of raw materials and despatch of aluminium. A 132kv electricity line supplies power via the National Grid from Wylfa Nuclear Power Station. The stack is a prominent landmark at 122 metres high.

Detailed recording by the Royal Commission was undertaken prior to closure of the works, both through ground and interior photography of the process, and on 13th January 2012, from the air resulting in stereo oblique recording of the main building complex.