During the Gallic Wars (58–50 BC), the Atuatuci held a fortress, besieged by Caesar in 57 BC, which has not yet been identified with certainty by archaeologists. In his account of the Siege of the Atuatuci, Caesar mentions that their stronghold was fortified by "stones of great weight", sharpened beams, and walls built with manned stations. The settlement was also described as "admirably fortified by Nature", surrounded by cliffs on both sides, and accessible only by a narrow route. According to Caesar, it was large enough to shelter at least 57,000 people.