Cae'r Tyddyn is a farm located approximately four miles east of Dolgellau, on the southern edge of Rhos Gwanas moor and at the northern end of the Bwlch Oerddrws pass. The first and second editions of the 25inch OS maps, published in 1889 and 1901, record only one farm on the site - Cae'r Tyddyn. More modern maps, however, indicate that there are now two farms located there - Cae'r Tyddyn and Cae Tyddyn Bach.
Source: modern and historic OS maps
M. Ryder, RCAHMW, 18th December 2018.