Glendalough

A glacial valley in the Wicklow Mountains with two lakes and the remains of a monastic settlement founded by St Kevin in the 6th century, including a 30 m round tower, churches and a cemetery of Celtic crosses. Walking trails lead along the lakes and up to the Spinc ridge, with views down over the Upper Lake.

The visitor centre explains the site. It's about an hour from Dublin; the St Kevin's bus runs daily. Car parks fill up at weekends. The Wicklow Way long-distance path passes through.