There are the remains of another underground structure located in the MT wood. This may have been an ammunition store or an observation post. This structure was connected to one of the shafts dug in the 1740s that gave access to the water tunnels that ran into Coleshill House.
There was a large pit dug alongside the path through the wood. It measures 2.5m wide by 3.5m long and 2.5m deep. It is thought that this was used as an ammunition or explosives store, with a ramp leading down into it.