Built in 1817 to commemorate the Duke of Wellington's victory at the Battle of Waterloo, the site had been closed for many years due to its dangerous state. After a commpetitive tendering process, SSHC were contracted to undertake the massive programme of masonry repairs. The challenges of this vast project were varied and exacerbated by the exposed and isolated nature of the site, combined with its height. The project involved dismantling and replacement of stone, repairing stone, stitching with bed reinforcement, tying with consolidation anchors, removal of vegetation, pack pointing, repointing, and grouting.

The on-site works were completed to time and to budget in May 2021. In  November 2021 Historic England took the Grade II* listed monumnet off the Buildings At Risk list.