Dorset contains 190 conservation areas, more than 1,500 scheduled monuments, over 30 registered parks and gardens and 12,850 listed buildings. Grade I listed buildings include: Portland Castle, a coastal fort commissioned by Henry VIII; a castle with more than a 1,000 years of history at Corfe; a Roman ruin described by English Heritage as the "only Roman town house visible in Britain"; Athelhampton, a Tudor manor house; Forde Abbey, a stately home and former Cistercian monastery; Christchurch Priory, the longest church in England; and St Edwold's church, one of the smallest.