Beautiful Lake Manapouri is within the boundaries of Fiordland National Park and the Te Wahipounamu World Heritage site. The lake is framed by the spectacular Cathedral Mountains and has four arms - North, South, West and Hope.
During the last ice age, glaciers originating in central Fiordland spread out to the east across the present sites of Lakes Te Anau and Manapouri, dumping great quantities of rock and gravel in long ridges. When the ice melted, lakes formed behind the ridges. Lake Manapouri is 440 metres deep in places and has 33 islands.
https://www.newzealand.com/nz/feature/lake-manapouri/