The oldest part of the structure is the 11th century tower. It is usually described as Norman. However, it could be pre-Conquest on the basis of a series of round window openings, like portholes: these small openings are found in Anglo-Saxon architecture and are sometimes called 'sound holes' although there actual function is unclear. The ones at Wendens Ambo are similar to late Saxon windows in St Bene't's church in Cambridge.