Lake Matheson is a small glacially formed lake 5km from Fox Glacier village, famous worldwide for its mirror reflections of Aoraki/Mount Cook and Mount Tasman at dawn. When the light and the weather cooperate, the lake surface doubles the mountains so perfectly that the horizon disappears and you are not sure which way is up. A 1.5-hour walking circuit of the lakeshore leads to the "View of Views" platform at the far end, positioned for the best angle on both peaks.
The catch is timing. The reflections require calm water, which means early morning before any breeze develops — and a clear sky, which on the West Coast requires some patience. Many visitors make two or three visits before getting the shot. If you do manage a perfect dawn here, it is one of the most photographed views in New Zealand for good reason.