Old Oswestry hillfort, Shropshire. Old Oswestry is a large and impressive early Iron Age hill fort in the Welsh Marches near Oswestry. It was occupied between the sixth century BC and the Roman conquest, probably by the Cornovii tribe. The complexity of its defences suggests several phases of development. The site was originally occupied by a few undefended round huts. These were then enclosed by a double bank and ditch enclosure spreading over 52,000 square metres. Entrances were placed through the enclosure at the east and west ends where the inner bank was pulled back inwards to create a more impressive gateway. These defences were later rebuilt and a third bank added on all sides except the south east where the hill's steep slope made further strengthening unnecessary. The western entrance was then remodelled with unusual rectangular hollows separated by ridges dug out and defended by outworks. Finally two further circuits of banks and ditches were added to the outside and a flanking bank placed alongside the eastern entrance. Although Old Oswestry was one of the most strongly defended hill forts in Britain there is no evidence that the Romans ever tried to besiege it. ?005 Credit:TopFoto / Fortean