70m, 2 pitches. 1).Start below the right edge of the Sentinel climbing up a groove to move right and belay on the arete.
2).Step left and climb up a crack through a bulge before moving up and left over a series of steps to the obvious groove/corner that forms the apex of the buttress. Step back right and then left again, to finish on the crest of the buttress - a good pitch. (or the original finish is to move right to the arete after the tricky crack/bulge and climb the right side of the arete to finish.