 The archaeologists D. J. Cathcart King and Leslie Alcock suggested that the castle was a ringwork – a type of fortification where earthworks formed an integral part of the defence.This was before excavation established that the first phase of the castle was a curtain wall and the earthworks seen today are the result of the collapse of the structure and accumulation of soil on top.Buckton is now understood to be an enclosure castle, with stone walls forming the key defence.