Great Walk, medium level as it is a constant incline. Around 3.5 hours there and back from Diamond Harbour. It is fully exposed to elements entire way.
Nice hike, great view from the top on Christchurch and its mountains in the back. Worth going to little Herbert to have a clear view on the Banks Peninsula.
A steep hike but the view on the way up and at the summit is well worth the effort. One of the best sights in New Zealand. A must do in the South Island