Overview
The stretch of the Glencullen River worth going out of your way for is the section through Knocksink Wood, just north of Enniskerry. The wood is a protected woodland, best known for its “petrifying” springs, seeps so rich in lime that they slowly coat moss, twigs and leaves in a stony crust of tufa. That, and the stands of old sessile oak, are the reason to come.
The river itself is an 11-kilometre watercourse (Abhainn Ghleann Cuilinn, the holly glen) rising at about 442 metres on the slopes of Glendoo, opposite Tibradden, on the border between southern County Dublin and northern County Wicklow. Below Enniskerry it’s also called the Cookstown River (An Chlóideach) before it joins the River Dargle near Bray. The valley follows a geological fault: Devonian granite to the north-west, Ordovician schist to the south-east, with the river cutting down through glacial till and gravels. Some of the granite quarried around Glencullen went into Dublin’s General Post Office.
Walking Knocksink Wood
Follow the public Knocksink Wood route and any signs at the entrance. The paths can be uneven and slippery, especially after rain. Stick to the marked paths, both to protect the fragile tufa deposits and because the woodland floor is a habitat in its own right, with rare plants like blue fleabane, ivy-leaved bellflower and yellow archangel among the ferns. The best of the wildflowers is spring and early summer.
Follow local signs for access and use designated public parking only. Check what facilities are available before you go, and pick up food and drink in Enniskerry.
The river and wildlife
The water runs cold and fast, which rules out swimming but makes the banks a good spot to sit and watch. Keep children back from the bank. Early spring and autumn bring the most bird movement through the valley.
Practical information
- Access – follow the signed public paths and leave the spring deposits undisturbed.
- Roadworks – check Wicklow County Council’s current works notices if travelling through Enniskerry.
- Getting there – public transport is limited: buses serve Enniskerry, and Bray has the nearest rail station, followed by a taxi or walk.
- What to bring – sturdy footwear; the paths get slippery after rain.
Nearby
Enniskerry has cafés, shops and a weekly market, and makes the natural base for a day here. For more river walking, the Avonmore River and Meeting of Waters is a short drive south into the Wicklow Mountains.