Glenmacnass Waterfall, Mountain waterfall in County Wicklow, Ireland.

Glenmacnass Waterfall drops 80 meters in three separate cascades over grey granite rock in the Wicklow Mountains. The water flows across multiple ledges, creating a series of distinct falls before reaching the valley below.

The Old Military Road was built in the early 1800s and passes near the waterfall as a strategic route through the mountains. This historic path still crosses the region today, linking different areas of the highland landscape.

The Irish name Gleann Log an Easa means 'the glen of the hollow of the waterfall', a description of the valley head where the river drops. The Glenmacnass River rises on the southeast slopes of Mullaghcleevaun and falls in three staggered drops to the valley floor, then runs on to join the Avonmore at Laragh.

The viewpoint sits near a parking area that fits several vehicles, requiring only a short walk to view the falls. The path is relatively flat and easy to navigate, though the hilltop can be windy and wet.

The waterfall sits at a geological boundary where grey porphyritic granite meets dark schist rock, creating a natural division in the landscape. This rock transition is visible in the different colors and textures that appear as water flows down the cascades.