Ireland consists of a mostly flat low-lying area in the midlands, ringed by mountain ranges such as (beginning in County Kerry and working counter-clockwise) the MacGillycuddy's Reeks, Comeragh Mountains, Blackstairs Mountains, Wicklow Mountains, the Mournes, Glens of Antrim, Sperrin Mountains, Bluestack Mountains, Derryveagh Mountains, Ox Mountains, Nephinbeg Mountains and the Twelve Bens/Maumturks group. Some mountain ranges are further inland in the south of Ireland, such as the Galtee Mountains (the highest inland range), Silvermine and Slieve Bloom Mountains. The highest peak Carrauntoohil, 1,038 m (3,405 ft) high, is in the MacGillycuddy's Reeks, a range of glacier-carved sandstone mountains. Ireland's mountains are not high - only three peaks are over 1,000 m (3,281 ft) and another 457 exceed 500 m (1,640 ft). Ireland is sometimes known as the Emerald Isle because of its green landscape.