This article analyses the gatehouse of the wealthy Benedictine abbey of St Benet's Holm in Norfolk, one of the set-pieces of English monastic architectural patronage in the fourteenth century. The ruinous condition of this building, and its sequestered location, means that it has attracted little scholarly attention in the past, and the neglect has been exacerbated by the presence of a brick windmill-tower superimposed on its remains four centuries after the gatehouse was built. This forced marriage, at once preposterous and compelling in effect, has absorbed most of the attention paid to the site, and because what is left of the gatehouse's main façade is embedded within the mill-tower, and thus difficult to photograph, its artistic uniqueness and quality of execution have been concealed. There has hence been no serious attempt to investigate or contextualize it (Figs 1, 2).