The most exciting and challenging section of the Tararua Main Range.
From Mangahuka follow the poled track south 100m to the summit and signposted junction (turnoff to Niell Forks). Continue along the main range, swinging west and dropping a narrow ridge to the saddle below. A couple of scrambles follow over the saddle - both roped, before you swing round the northern face of Tunui to a slight saddle between Tunui and a knob to the north. Swinging back towards the main range the poled route sidles a very steep tussock face. The face has eroded badly in recent years and is now roped across a small creekhead. This takes you to the base of the steel ladder between the peaks Tunui and Tuiti. The ladder is just that - a very long,tall ladder. We can all climb them: I've done it carrying the dog 3 times!
The tricky bit is when you get off the top. You step right off the top of the ladder, then scramble a steep rockface onto Tuiti, with large bluffs below. This section was the worst, but now has a good steel rope to hold onto.
Once on Tuiti things become easy. A standard tramp along a narrow ridgeline follows for 1km west to reach the 1st peak of McIntosh. Blue poles on the 1st summit mark the junction with a track dropping north to Penn Creek Hut.