 Agnes Lady Fountain took over the lease after his death in 1917.She agreed to a plan to protect the castle, under which she purchased the freehold and transferred this to the Society for the Protection of Ancient Buildings in 1937; then, once the leasehold on the property had expired, the castle was passed into the guardianship of the Ministry of Works in 1948.The site was excavated by S. Rigold between 1953 and 1961 while the castle was being restored, and again between 1966 and 1967 during work to install a new bridge over the moat.