Abercegir is a small, linear village located approximately three and a half miles north east of Machynlleth. It is situated at the point where the Cegir stream meets the Gwydol river, hence the village's name (Abercegir means 'Mouth of the river Cegir'). Abercegir's position at the confluence of the Cegir and the Gwydol made it an ideal location for mills, and in the nineteenth century Abercegir had three. The first and second editions of the 25inch OS maps, published in 1887 and 1901, record these mills as: 'Factory Isaf (Woollen)' - NPRN 41022; 'Factory Uchaf (Woollen)' - NPRN 40999; and 'Pandy' - NPRN 307112. Factory Isaf was 'reputed to have been operational from 1804 to 1964' and is 'believed to be one of only two complete fulling mills in Wales, the other being Moelwyn Mill, Blaenau Ffestinog (NPRN 40924)'
Abercegir Wesleyan Methodist chapel (NPRN 11278) was built in 1819, rebuilt in 1826 and rebuilt again in 1865. On 21st June 2016, full planning permission was granted to convert the chapel into a three-bedroom residential dwelling.
Sources: modern and historic OS maps; COFLEIN database; Morris Marshall and Poole information leaflet about Abercegir chapel.
M. Ryder, RCAHMW, 18th December 2018