Mount Cook is the highest mountain in New Zealand. Its height since 2014 is listed as 3,724 metres, down from 3,764 m before December 1991, due to a rockslide and subsequent erosion.It lies in the Southern Alps, the mountain range which runs the length of the South Island. A popular tourist destination,it is also a favourite challenge for mountain climbers. Aoraki / Mount Cook consists of three summits, from South to North the Low Peak (3,593 m or 11,788 ft), Middle Peak (3,717 m or 12,195 ft) and High Peak. The summits lie slightly south and east of the main divide of the Southern Alps, with the Tasman Glacier to the east and the Hooker Glacier to the southwest.
There was a large rock fall in 1991 that turned the summit into a knife-edge ridge and reduced the height of the mountain by an estimated 10 m or so at that time. Aoraki / Mount Cook was measured in 2013 to be 3724 m, which is 40 m down from its pre-1991 rock-fall measurement.