Norham is laid out as a normal motte and bailey castle but the wards are both larger than usual to accommodate the large garrison and provide quarters for the prince bishop and his retinue when they visited the border.
The main entrance is by the West Gate (Marmion's Gate). The core of the building is Norman, comprising a tunnel-vaulted entrance with shallow pilasters against the walls. In the fourteenth century it was closed but reopened in 1404 and provided with a barbican and a drawbridge. The drawbridge pivoted round its centre and when it was raised its inner end sank into a pit which can still be seen under the modern* bridge. The north wall of the Outer Ward runs along the brink of a steep bank which descends to the Tweed. There are three low arches, built in 1509, which are casements with port-holes for small cannon.
Where the wall joins the inner ward is the fifteenth century chapel whose undercroft was converted into a stable in 1521. Only part of this underecroft still stands. The buildings at this point inside the moat are partly connected with washing and partly with the flooding of the moat.
The Inner Ward is entered by a modern bridge* which is on the site of its medieval predecessor. The gateway is in poor condition. Against the north wall is the Great Hall of Norham Castle which was rebuilt early in the sixteenth century. The adjoining Great Chamber is contemporary. As usual the kitchen (with its oven). pantry and buttery are at the screens passage end of the Hall.
The inner bailey is now grassed lawns in one corner of which is a deep well, probably used for drinking water in times of siege.
The Keep measured eighty-four by sixty feet and was originally three storeys high and its high-pitched roof line can be traced on its east wall. In 1422-25 the keep was rebuilt from the second storey upwards to a height of five storeys and a spiral staircase added. The Norman keep was divided unequally by a cross-wall. The south half of the basement is barrel vaulted, the north half has early Norman rubble vault of four bays with big flat unmoulded transverse ribs springing from pilasters. In Norman times the keep was entered by an external staircase on the first floor from which entrance to the basement was possible. On the first floor is a Norman fireplace in the south wall and a magnificent arched niche at the east end.
On the south side of the inner ward is Clapham's Tower. It has a pointed front and portholes for artillery. It was built early in the sixteenth century. The neighbouring oblong tower is of fifteenth century construction. The east side of the Outer Wall is Norman work and the Sandur's Tower was added probably in the thirteenth century.
The original south curtain wall of the outer ward was probably for long only a wooden palisade and ditch. The round-fronted turrets were built in the thirteenth century, the polygonal turret with well-preserved gun-ports is of sixteenth century workmanship as is its companion on the west. In front of the Sheep Gate was once a wide moat. The upper storey was used as the constable's lodging. In the south curtain wall are several mysterious arches. The only suggestion for their use is that they were the foundations of a stone curtain wall built on an earlier earth wall.
*Footnote: The modern bridges at Marmions Arch and leading to the Inner Ward were built around 1950 by my father Tommy Simpson.