 The castle 's state was assessed in 1961 , and the cost of repairs estimated at £ 30 @,@ 000 ( equivalent to £ 1 @.@ 1 million in 2009 terms ) . The Ministry of Public Building and Works took over care of the castle from the Corporation of Rochester in 1965 . Records of the Ministry 's conservation work have gone missing , so precisely what was done is unclear . Between 1962 and 1965 the council removed buildings from the castle 's ditch . Guardianship transferred to English Heritage in 1984 . Since 1995 the City of Rochester has been responsible for daily management of the castle . Descaling at the start of the 21st century contributed to the decay of the keep , and one of the mural towers was in need of maintenance . Due to the decayed state of the keep , public access is restricted and netting has been erected to protect visitors . The possibility of adding floors and a roof to the keep was discussed in the 1970s and 1990s , but there were concerns that a roof would change the climate within the building . The castle is a Scheduled Monument , a " nationally important " historic building and archaeological site which has been given protection against unauthorised change . It is also a Grade I listed building , and recognised as an internationally important structure . The castle is open to the public . 
