The Byzantine Fort marks a later chapter in Timgad's life, after the precise Roman grid had already begun to fray. Its heavier walls and defensive purpose contrast with the forum, theatre, and triumphal arch, reminding you that this was not just a frozen Roman showpiece but a town reused in changing political and military conditions.
It is worth seeking out once you have walked the main streets, because the fort shifts the story from imperial planning to survival. The stonework is rougher and less elegant than the classical monuments, but that is exactly why it matters: Timgad's ruins are a palimpsest, not a single moment preserved in amber.