Climb up the 4 bolts, and then follow the crack. At the top of the crack move over the bulge and straight up to the anchor. Alternatively, traverse right at the top of the crack to a second crack and climb to the anchor from there.
Same starting point as 'Unknown', but after the first bolt, move left towards the obvious crack. A 60 m rope will bring you just down to the ledge, but a 70 m will make this easier.
4 bolts, half rack, 2 bolted anchors at the top with chains.