Colchester is well known for its Roman remains, and the Balkerne Gate is the most complete Roman town gateway in Britain. Built around AD 55, it started life as the main entrance to the town but was later turned into triumphal arch. Ten years later it was incorporated into the new town walls, but blocked up four hundred years after that to strengthen the town's defenses. The Gateway was only uncovered around 100 years ago, which helps to explain its survival.