I was speaking to the proprietor of the camera shop in Bath, the one near the cathedral, and he said there's something similar in his cellar, which he never quite dared knock down, but that Bath is said to be riddled with tunnels, and a heap of rumours surrounding them. I suspect the most mundane reason that they were shortcuts for the toffs to go to church when it was wet.
I know the odd cataphile - the name for those who explore Paris underground - and the whole concept is fascinating. If we have any cataphiles on this forum, I'd love to see your posts! I've used the tunnels in a couple of novels, from photos and descriptions of others, but I'm severely claustrophobic and I don't think I'd even manage the public parts. But for a claustrophobe, I am fascinated by tunnels. I wonder if the bricked up doorway in this cellar was in any way connected with smuggling, or was just an extensive cellar? another tunnel there is said to exist is in Blytheborough, Suffolk, between the White Hart on the river and the church on the hill. That one would have been about smuggling, a national sport in the vicinity.