The Chapel of St Peter on the Wall, Bradwell-on-Sea, Essex, England. The Chapel is a Grade I listed building and among the oldest largely intact Christian church buildings in England still in regular use, dating from the 7th century. The Chapel is assumed to be that of "Ythanceaster" (Bede, Historia Ecclesiastica 3.22), originally constructed as an Anglo-Celtic Church for the East Saxons in AD 654 by St Cedd, astride the ruins of the abandoned Roman fort of Othona.
St Peter's on the wall, Bradwell. Anglo-Saxon architecture - Wikipedia, the free encyclopedia