county were extended in 1957 by the Local Government Act which "detached lands from the County of Dublin and from the jurisdiction and powers of the Council of the County of Dublin" near Bray and added them to the County of Wicklow. Geography Location Wicklow is part of the Eastern and Midland Region of Ireland, within the province of Leinster. It is bounded by four counties, Dublin to the north; Kildare and Carlow to the west; Wexford to the south; and the Irish sea to the east. Wicklow is the 17th largest of Ireland's 32 traditional counties by land area, and the 16th most populous. It is the fourth largest of Leinster's 12 counties by size and the fifth most populous. The county is named after the town of Wicklow, located approximately south of Dublin, the capital city of Ireland. The Wicklow Mountains are Ireland's largest continuous upland area and occupy a significant portion of the county, spanning the entire centre of Wicklow and stretching into Dublin and Wexford at their southern and northern fringes. Lugnaquilla, at above sea level, is the tallest peak in the range, the highest mountain in Ireland outside of County Kerry, and Ireland's 13th-highest mountain overall. The Wicklow Mountains National Park, located in the middle of the county, is a dedicated protected area covering , making it the largest national park in Ireland. The Wicklow Way was the first long-distance trail in the State, and crosses the range for . Geology The Wicklow Mountains are centred on the Leinster batholith and are primarily composed of granite surrounded by an envelope of mica-schist and much older rocks such as quartzite. Covering , the Leinster batholith is the most expansive mass of intrusive igneous rock in Ireland or Britain. The oldest rocks in the county are the quartzites of the Bray Group that include Bray Head and the Little Sugar Loaf and Great Sugar Loaf mountains. These metamorphosed from sandstone deposited in the deep waters of the primeval Iapetus Ocean during the Cambrian period (542-488 million years ago). As with much of Ireland, Wicklow's terrain was sculpted by successive periods of glaciation during the quaternary. Weathering and erosion by ice carved out long valleys known as glens (from the Irish gleann) such as Glenmacnass, Glen of the Downs, Glenmalure, Glen of Imaal, Glencree and Glendalough. The Irish Sea Ice-Sheet began to retreat shortly after the Last Glacial