Officials are examining the mysterious odour with the gravity usually reserved for unexploded ordnance, while the manholes themselves remain unavailable for comment.
Plans for Walnut Court in Kembrey Park would see the former utility headquarters converted into homes, with sixteen bins, 177 parking spaces and, locals suspect, unusually good plumbing.
Despite a full road closure, a six foot sign, and a crater you could lose a Nationwide branch in, motorists keep turning up like it is a tourist attraction with a car park at the end.