I've had a prompt and very helpful email from Chris Lloyd at the Echo responding to the comments in Stepping Back in Time below. Echo Memories has covered the property Mike Barker refers to on Bakehouse Hill, and Chris takes up the story;
"I reckon the "tunnels" are in fact the old bakehouse built around 1820. They extended some way under the Market Place and were closed by an 1875 Act of Parliament which banned bakehouses which had been excavated beneath public thoroughfares. I have been told that they stretch underground to the edge of the pavement (if memory serves me correctly, there is/was a phone box on the corner of the pavement in the Market Place). In fact, the reason the pavement is so uncommonly wide here is because of the underground remains - or so I am told.
"I've found that most stories of tunnels tend to be just stories. I am always told that the town centre is built on shifting or running sand - I believe the Pedestrian Heart works have confirmed this, and one of the reasons the old High Row was always tumbling towards the Skerne was because of it - which I doubt would support the existence of tunnels."
On the much-debated apostrophe for Mechanics Yard (sic), Chris comments,
"It was named after the Mechanics Institute and its forerunners, so I think it is plural. But does it need an apostrophe at all if it was just a yard that was habitually full of mechanics rather than them possessing it in any way? All of which brings me to another highly important puzzler: does Darlington have a Market Place or a Market Square?"
In the light of Chris' comments, and advice from Town Officers on the cost of taking up the flags, re-engraving and then re-siting them again, I think it's probably best if Mechanics Yard remains unadorned by any punctuation. That brings this issue to a close. Chris emailed me the two relevant articles from Echo Memories about these issues, but I'm afraid there wasn't room to publish them here - if anyone would like them, I'd be happy to email them on.