The building consists of two late
Norman archways, a
carriage gateway and a smaller
postern gate for pedestrians, surmounted by a late
Perpendicular gatehouse, with an adjoining tower. The unweathered appearance of the archways led to a public debate between 19th century commentators as to whether the archways had been rebuilt since the 12th century, but the prevailing view, as argued in the 19th century by
George Edmund Street, is that they are probably the original ones. Both the north and south arches of the carriage gateway are densely decorated with carved
mouldings. Inside is a
ribbed vault and walls with carved interlaced
arcading. The arcading contains pointed arches, which arise from the intersections of interlaced round arches, just as in the cathedral's
chapter house. The similarities in the arcading, and in the two buildings' decorative patterns using a variety of motifs like chevron and nailhead, support the dating of the archways to about the same time as the chapter house, in the 12th century. The southern side of the carriage gateway is the most elaborate, with the archway having four courses of moulding. The postern gate has carved mouldings around the northern arch but is unvaulted and otherwise plain. The gatehouse and tower were additions by abbot John Newland around 1500. The gatehouse is embellished with two-storey
oriels with
mullion and
transom windows, two-storey statuary niches and panelled
parapets. These structures were restored by
John Loughborough Pearson in 1888, who succeeded in retaining many of the features of their original design. He restored the oriels, which at some point had been replaced by sash windows. The single-storey eastern extension is also 19th century. ==Influence==