PENTLAND HILLS, a range of hills in Scotland, in the counties of Edinburgh, Peebles, and Lanark, extending from the distance of 43 miles S. by W. of Edinburgh for about 16 miles in a S.W. direction. They consist of porphyry, with boulders of granite and gneiss; are partially cultivated, and afford good pasture for sheep. The highest summit is East Carnethy Hill, near the middle of the range, 1878 feet above the sea.