it is part of the southern alps mountain range and is flanked by the hooker glacier to the southwest and the tasman glacier to the east. the mountain has three peaks: the south peak being the lowest at 3,593m/11,788 ft., the middle peak at 3,717m/12,195 ft. and the north peak being the highest at 3,724m/12,218 ft. this is the height of the north peak after the landslide of december 1991 which took 30 meters off the top and also turned the summit into a knife-edge ridge.