I recently chanced on the Mayfair sim, which is the location for the Celoe and Mon Tissu shops. It's modelled on the prosperous London district.
The shops exclusively sell mesh items, primarily clothes, and Mayfair is described as a mesh-only sim, the first in SL. I did detect a few prims in the vendors, but apart from that, I could believe there's not a single prim or sculpt anywhere.