Rotopounamu fills a crater nestled into the western side of Mount Pihanga. It is nine metres deep and covers one square kilometre. The name of the lake comes from the Maori words 'roto' (lake) and 'pounamu' (greenstone).
Beginning opposite the parking area, the track winds gently uphill to the track junction. To walk around the lake, turn right and follow a short section of gravelled track before dropping down towards Five Minute Beach. Here a broad tree stump provides a good spot to view the lake.
Long Beach sweeps along the eastern side of the lake and is an ideal spot for a picnic or rest stop. There is a toilet here.
The track continues to the northern shore where three of the lake's four tributary streams enter the lake. The lake usually has no visible outflow, however when the water levels are low a small outflow can be seen near the shore on the southern side of the lake.
Continuing on, you pass Ten Minute Beach and soon return to the track junction. From here it is downhill to the carpark. Allow two hours for a leisurely walk around the lake.
From the road, take the track up to the junction and turn left. This short 20 minute walk will bring you to Ten Minute Beach, a pleasant picnic and swimming spot in summer.