None of Hadrian’s Wall has been reconstructed or rebuilt to its full height on its original line. However, John Clayton consolidated large stretches of the central sector curtain wall, where it fell within his estate, by replacing some of the fallen facing stones in a drystone walling technique, thereby forming a wall of a uniform height. This so-called Clayton Wall is characteristic of the portion now owned by the National Trust and, in the past, led to disagreement between the Ministry of Works (later Department of the Environment) and the Trust. When repairs became necessary, the Trust preferred the wall consolidated to their style, whereas the Ministry workmen consolidated ‘as found’, without replacing fallen facing stones. At one point, workmen were even instructed to sneakily dismantle some of the Trust’s repairs to the curtain wall, but in the end a compromise was reached. One other section of rebuilt wall is at Hare Hill (NY 563 646), where the facing stones were replaced in the 19th century (although the core is original).
Further reading: Leach and Whitworth 2011