Lake Pukaki

Pukaki is fed by the Tasman and Hooker glaciers through the Tasman River, and the meltwater carries an enormous load of rock flour - rock ground to particles fine enough to stay suspended indefinitely. Those particles scatter light in a way that produces the lake's particular opaque milky blue, quite different from the clear blue of a mountain lake, and it changes with the season and the light. The lake was raised twice for hydroelectricity, in 1945 and again in 1979, so the current shoreline is not the natural one. What makes it more than another pretty lake is the alignment: from the southern end the valley points directly at Aoraki, forty-odd kilometres away, so on a clear day the mountain sits at the head of the water. The main lookout on SH8 is where every tour bus stops; quieter pull-offs run up the eastern shore road toward Mount Cook Village.

What you actually see

• The rock-flour blue - opaque and milky, not clear water.
• Aoraki at the head - the valley aimed straight at the mountain.
• The lookouts - the main SH8 stop and quieter ones up the east shore.
• The raised shoreline - the result of two hydro schemes.

When to go

Any season - winter gives the sharpest air and snow on the peaks. The mountain is often in cloud, so a clear day matters more than the month. Early or late light is best.

Honest expectations

Aoraki is hidden by cloud on a large share of days. The main lookout is crowded with coaches through the middle of the day. The water is glacial and swimming is genuinely dangerous cold. Wind is constant.

Nearby

Mount Cook Village and the Hooker Valley are north; Tekapo and Twizel are on the highway.