The workshop mound [A03-330] forms the largest and highest density of flaked obsidian observed in the Upper Colca project region. The 1x1m test excavation in this mound (Section 7.4.2) revealed episodes of reduction activity that generated cultural levels with distinctive concentrations of knapping debris associated with early stage reduction. The flake densities attenuate away from the mound center where the test unit was placed, and immediately south-west of the mound a corral is evident that is probably relatively ancient. One possibility is that animals were loaded with obsidian inside the corral subsequent to knapping at the workshop.