20120814-187-189-hdrR5-morocco-fes-tannery
The larger tannery, and what most tourist guides are referring to when they mention the Fes tanneries. Apparently there are some smaller and quite unimpressive ones around the medina that kids will try to lure you into. Beware, as always.
Photo taken from the shop (it's effectively the only way to see the tannery at all, unfortunately) on the north side. The shop on the west side seemed a bit pushier, although the distinction there is subtle at best.