The project, explains Jeremy Ashbee, head properties curator at English Heritage, was “very much to maintain Clifford’s Tower as a ruin and not pretend that it is something it isn’t. If we had recreated it as a building it would have been wrong on so many levels.”

Not least among the problems of recreating it as a building would have been to decide on which era and for what use, as it served as seat of power for all of the North of England through medieval times and subsequently found uses as treasury and armoury, being a stronghold during the Civil War, before being devasted by fire in 1684. The shell remained while most of the rest of the castle was gradually lost over time, and the Tower became a monument within prison grounds during the 18th and 19th centuries.

This current project was therefore to preserve and protect the ruins, particularly vulnerable parts like the upper Tower walls, and provide a more valuable public resource.

The solution was...