Tyddyn-Mawr farm is situated half a mile south east from the village of Arthog and two and a half miles north east of Fairbourne. It appears on the 1st edition and 2nd editions of the 25inch maps, published in 1888 and 1901. About 250 metres north east of Tyddyn Mawr there was a Tyddyn Bach on the 1st and 2nd editions of the OS map, although it does not appear on the modern edition.
Source: modern and historic OS maps
M. Ryder, RCAHMW, 5th October 2018.