The Cogs are the industrial base of Sharn. The mighty artificers of House Cannith aided King Galifar in reconstructing Sharn after the War of the Mark. In so doing they created a means of extracting raw materials from the lava flows deep beneath Sharn. The Cogs are hot and sulfurous. The workers here toil in dim corridors. Tenements for the city's poor and its more monstrous inhabitants exist here in three wards. The Cogs also connect to the abandoned Undercity of Sharn. When the city was re-inhabited, the Undercity tunnels were abandoned because of their association with House Tarkanen and the old, Dhakaani ruins.