Glendalough boasts a beautiful natural landscape and a religious site constructed during medieval times. It provides an ideal day trip from Dublin.
The Wikipedia site is full of interesting information about the place. It starts by explaining:
Glendalough or Glendaloch (/ˌɡlɛndəˈlɒx/ glen-də-lokh; Irish: Gleann Dá Loch, meaning “glen of two lakes”) is a glacial valley in County Wicklow, Ireland. It is renowned for its Early Medieval monastic settlement founded in the 6th century by St Kevin, a hermit priest, and partly destroyed in 1398 by English troops.