Raised shortly after the Norman Conquest, Pickering was an early motte and bailey castle - a simple, timber construction built on top of a grassy mound, surrounded by earthen banks and ditches. The remains of the stone buildings now sitting on top of the mound, and scattered around the inner bailey, date from the 13th century, and the curtain wall with its three towers date from the reign of Edward II.
Little survives of the shell-keep - a small section of flat, external walling with a circular inner wall, at one time containing several lean-to buildings. Originally the keep had two entrances: the doorway and steps of the lesser entrance to the east can still be seen, although the archway to the main entrance to the west has completely disappeared.
Located at the original entrance to Pickering Castle is the two-storey, 12th century Coleman Tower. At first floor level this tower would have housed the soldiers who guarded the castle entrance, and below was most probably the former prison, before it was re-sited in the Mill Tower. Within the inner bailey, the chapel is the only building to have a roof, although this dates from later restoration. Most of the buildings are at foundation level only, with the 'new' 14th century hall situated between the chapel and the curtain wall, and a range of domestic buildings assembled from the new hall to the entrance. The old hall, situated close to the curtain wall behind the chapel, is the oldest surviving stone structure in Pickering Castle, dating from the early 12th century.
Much of the 14th century curtain wall, and the three square towers set within the wall, have survived to a good height. From documentary records, it is clear that Pickering Castle was regularly maintained, albeit on a small budget, but inevitably some of the buildings were neglected and gradually deteriorated with age. By the mid 17th century, the Pickering Castle's useful life had come to an end, and it was left to decay gracefully for the next 250 years. In 1926 it came into the possession of English Heritage who helped breathe life once more into these old Yorkshire ruins.