Rear of North Door. The north door is Saxon, dated 1020 if contemporaneous with the doorway, but the wood is dated by dendrochronology (study of tree rings) to around 1034-1042. It is the oldest door in Essex. It consists of plain oak boards joined by undecorated bands of iron on the front. These are riveted through to circular wooden bars on the back. It was formerly covered in cowhide.