 In 1890 the Prison Commissioners agreed to declare Clifford's Tower a national monument and to conserve it as a historic location.In 1902 Clifford's Tower was given to the York Corporation, together with a grant of £3,000 (£242,000 at 2009 prices) arranged by Lord Wenlock for conservation and repairs.The removal of the talus and the damage to the castle stonework in the 16th century had put excessive pressure on the supporting motte, causing a recurrence of the 14th century subsidence.