Glendalough (ˌɡlɛndəˈlɒx; ) is a glacial valley in County Wicklow, Ireland, renowned for an Early Medieval monastic settlement founded in the 6th century by St Kevin. From 1825 to 1957, the head of the Glendalough Valley was the site of a galena lead mine. Glendalough is also a recreational area for picnics, for walking along networks of maintained trails of varying difficulty, and also for rock-climbing. Kevin, a descendant of one of the ruling families in Leinster, studied as a boy under the care of three holy men: Eoghan, Lochan and Eanna. During this time, he went to Glendalough. He was to return later, with a small group of monks to found a monastery where the 'two rivers form a confluence'. Kevin's writings discuss his fighting "knights" at Glendalough; scholars today believe this refers to his process of self-examination and his personal temptations. His fame as a holy man spread and he attracted numerous followers. He died in about 618, traditionally on 3 June. For the next six centuries, Glendalough flourished and the Irish Annals contain references to the deaths of abbots and raids on the settlement. Circa 1042, oak timber from Glendalough was used to build the second-longest Viking longship recorded (circa 30 m). A modern replica of that ship was built in 2004 and is currently located in Roskilde, Denmark. At the Synod of Rath Breasail in 1111, Glendalough was designated as one of the two dioceses of North Leinster. The Book of Glendalough was written there about 1131. St. Laurence O'Toole, born in 1128, became Abbot of Glendalough and was well known for his sanctity and hospitality. Even after his appointment as Archbishop of Dublin in 1162, he returned occasionally to Glendalough, to the solitude of St. Kevin's Bed. He died in Eu, in Normandy in 1180. In 1176, the Annals of Tigernach report that Glendalough was 'plundered by the foreigners'. In 1214, the dioceses of Glendalough and Dublin were united. From that time onwards, the cultural and ecclesiastical status of Glendalough diminished.