Cader Idris ('Chair of Idris,' a reputed giant), a picturesque mountain in Merionethshire, Wales, 5 miles SW. of Dolgelly. It consists of an immense ridge of broken precipices, 10 miles long, and 1 to 3 miles broad; the highest peak reaching an elevation of 2914 feet. It is composed of basalt, porphyry, and other trap rocks, with beds of slag and pumice. The view from the summit, which is very extensive, includes the Wrekin in Shropshire, and St George's Channel almost to the Irish coast.
Cader Idris
Chambers's Encyclopaedia, Volume 2: Beaugency to Cataract, p. 614
Source scan(s): p. 0627