3rd instanced zone in Zek. This uses the same internal zone name as The Tallon Hording Halls and The Sullon Mines (orcishwastes_mini01).
I zoned into The Sullon Mines tonight and the right map comes up correctly (although zonerect is off a bit). When I zoned into this 3rd zone, the map for Tallon Hording Halls came up.
Anyways, here's the datafile and preview for the map for The Darkened Den.