Desolate and utterly deserted, the Glenmacnass Valley, a stretch of wild bogland between the Sally Gap crossroads and Laragh, is one of the most beautiful parts of the Wicklow Mountains, and the sense of isolation is quite dramatic. The highest mountain to the west is Mullaghcleevaun (848m), and River Glenmacnass flows south and tumbles over the edge of the mountain plateau in a great foaming cascade. It's 9.5km north of Glendalough. There's a car park near the top of the waterfall.
Be careful when walking on rocks near Glenmacnass Waterfall as a few people have slipped to their deaths here. There are fine walks up Mullaghcleevaun and in the hills to the east of the car park.