The nave of St Mary's, Birchanger was built around 1125 and and the chancel built 100 years later. Originally the church had a round tower but that was destroyed in the 18th century. The church was substantially restored in the 19th century but two Norman doorways remain, on the west and south sides. The west doorway was probably originally on the north side and moved when the tower was knocked down. The south doorway contains a feature unique in Essex: there is a figurative carving in the tympanum. The carving is of a lamb, possibly symbolising the Lamb of God.