Glendalough (; Irish: Gleann Dá Loch, meaning "Valley of two lakes") 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.