This virtual tour starts at the Castle, which had protection on the west and south-west sides from the Castle Mill Stream and the Trill Mill Stream, and a moat on the other side.
The Castle was built into the western side of the town defences for William the Conqueror in 1071. Only St George’s Tower (shown above and below), the mound, and the base of the Round Tower survive.
St George’s Tower is four floors high, and its walls are 9 feet thick at ground level. One of the earliest stone towers in England, it was both the tower of St George’s in the Castle Chapel and part of the castle’s fortifications.
The Castle was used as an administrative centre of the county (with the shire courts and assizes held here from the thirteenth century until 1577).
The gaol, which adjoined St George’s Tower, was used to house prisoners from Oxfordshire and Berkshire; but in 1236 it was also used for the University’s “rebellious scholars”.
Above and below: Romanesque columns in the Crypt of the Chapel of St George’s in the Castle
Above: The Castle mound (or motte) is 64 feet high and 81 feet in diameter at the top. It was probably created from the soil dug out to make the moat, and originally there would have been a wooden tower on top. In the thirteenth century, when the motte was made higher, a well chamber, 20 feet below the surface, was built at the top.
Above: the Castle in c.1905, showing the doorway of Empress Maud/Matilda
The medieval town had no proper west wall: the north wall and the south wall each tapered inwards to meet at the boundary of the large castle site.New Road (which, as its name suggests, is “new”, having only been created in the 1770s) makes it difficult to envisage the extent of the castle wall, which in fact stretched as far as Bulwarks Lane, enclosing 2½ acres of land.
This virtual tour starts in Bulwarks Lane, which is up some steps at the east end of New Road, opposite Castle Street.
Victoria County History: History of the County of Oxford, Vol. IV, pp. 296–300: