He also had men build tunnels. One entrance to the system even has been found in the basement of his former house. But why tunnels? Did he ask them to build his tunnels arbitrarily, for no other purpose than to be paid for work? It seems extraordinary. And yet there are no known records from Williamson’s time which offer anything like an explanation for their construction.
Instead, succeeding generations and historians have had to guess – leading to all manner of speculation. Perhaps Williamson wanted secret passages to get to and from buildings in Edge Hill. Or was a smuggler and needed the tunnels to carry out covert operations.
Or maybe he and his wife belonged to a fanatical religious cult that anticipated the end of the world, and his tunnels were designed to provide shelter during the apocalypse. Apparently, someone once made the suggestion casually on television, and the idea since stuck.
Those who have worked on the tunnels have now developed a new, somewhat more satisfying theory. Bridson points out a series of markings in the sandstone that he says are indicative of quarrying. There are channels to drain rainwater away from the rock while men worked, blocks out of which sandstone could be hewn, and various niches in the walls where rigs were once likely installed to help with extracting the stone, commonly used as a building material.
Bridson believes that before Williamson came along, these pits in the ground already existed. But it was Williamson’s idea to construct arches over them and seal them in. Properties could then be built on top of the reclaimed land – which otherwise would have been practically worthless.
The land development theory is an interesting one. Williamson could benefit in two ways: by selling the excavated rock from below the surface and then also selling the land above it. Now, there might be separate rights to the above ground and below ground space but no such issues likely hindered Williamson.