This L-shaped cavern was uncovered during construction of the Williamson Student Village in early 1999. It was excavated to a depth of twenty feet without reaching the bottom. In it were a number of large concrete pillars which had been put in in the 1930s to support the Paddington Gardens flats when they were being built. However, one could still see the tell-tale dressed sandstone blocks in the side walls and remnants of the original brick arched roof. This cavern, likely to have been one of the junction points to which long tunnels connect, had to be re-filled to allow construction work to continue but that does not preclude accessing it again in future by coming at it from the side (under ground) rather than from above.