Irish: Abhainn Ghleann Cuilinn
Glencullen is the most northerly of the eastern Wicklow Mountains’ glens. The river valley runs for a distance of 9.5km in a northwesterly direction from Enniskerry, crossing the county boundary to Tibradden, Co. Dublin. The valley floor is partially filled with glacial till and glaciofluvial gravels. The greater extent of the valley sides is vegetated (gorse, bramble, and broadleaf deciduous woods). Nearer the riverbank, the terrain is vegetated with wet woodland, heath and a number of tufa (springs and seepage areas). Knocksink Wood is a popular amenity area running along the glen.
The Glencullen joins the River Dargle just west of Bray near the N11.