Large expansion of Roman territory was in a less advanced state. Transhumance was spread in the countryside of Numidia. These pastoral and semi-nomadic communities were often on the move, carrying their oven-shaped huts (called mapalia). As Roman estates expanded in North Africa, the pastures of those communities were hugely reduced and their movements more tightly regulated. Even in Spain the north was much less developed, and inhabited largely by a Celtic-speaking peasantry that lived in hilltop villages called castella.