The North Gate

The Roman town defences were built in two phases, both of which survive today.

The north gate as it would have looked in the third century AD, after the rampart had been strengthened with a wall. The carriage way was about four metres wide, sufficient to allow a single cart to pass.(Drawing by Ivan Lapper) © English Heritage In about AD 200, a rampart of earth and clay was constructed, though it featured masonry gatehouses. One of these gatehouses, built in stone and tile, still stands. It led north towards Dorchester on Thames. Several of these gatehouses survive. Perhaps the best preserved is the North Gate, guarding the road north to Dorchester on Thames. There is even a recess indicating the position where the gate would have hung. Five of the seven town gates provided access to roads which led to other major towns in southern Britain. © English Heritage
 

On either side of this gate are the grassed-over remains and in about AD 270 these defences were strengthened with a massive stone wall.

While the defences offered general protection from enemies, they also allowed for control of all traffic entering and leaving the town. Major, dual carriageway gates were situated to the east and west of the town and single carriageway gates to the north and south.