SNOWDON (Wyddfa, view-place, Eryri, eagle-place), the highest elevation in N. Wales. It is formed chiefly of slates, grits and porphyries of the Cambrian and Silurian systems. It consists of five " ribs " converging at the summit, 3560 ft. above sea-level. Between these lie such depressions as Cwm Glas (blue or green vale) to the N., and Cwm y llan (clearing, town or church vale) to the S. Snowdon is demarcated from the surrounding hills by passes famous for their scenery, such as that of Llanberis (q.v.) to the N.E. and Aberglaslyn to the S. These two passes are joined by Nant Gwynnant (stream, or valley, of the white or happy valley, or stream), skirting the S.E. flanks of the Snowdon massif. Nant Colwyn runs N.W. to Carnarvon. A rack-and-pinion railway (opened in 1897) ascends from Llanberis to the summit of the mountain (4! m.). Snowdonia, as the locality is sometimes called, contains several lakes, e.g. Peris and Padarn at Llanberis; Glaslyn and Llydaw between Cribgoch (red crest) and Lliwedd; Cwcllyn and others W. of the hill itself; and Gwynnant and Dinas (Y Ddinas) in Nantgwynnant.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)