The smelting pit was a natural place of molten metals when the Quintesson's arrived they simply modified to allow them to skim off the top layers of material to reuse. The cause of the hot spot isn't known to the scientists as the heat produced the lower their probes went the temperatures got near to that of a star which should not be possible on a populated planet. It was found by Extempaxia that even non-cybertronian metals can be converted to the living metal in the forge and has used many contracts for the military bots as ways to get more exotic metals to test new possible bot frames.
Purpose / Function
The place the Quintesson's dump all broken machines and slaves to reclaim what living metal they can.
Sensory & Appearance
Quintesson Forge Works dug around the pit to create an overflow point to several automated molding stations to create bot skeletons and simple blocks of living metal from the refuse they throw in.
The original rim of the pit was made of a seemingly non-native material that trapped all heat from radiating from the edges forcing it up into the atmosphere of the planet. There were visible gliffs and runes upon the ring until the Quintesson Forge Works destroyed a section of the lip to build their automated mold station.