The weights from Thonis-Heracleion offer a new perspective on trading activities and mechanisms in the emporium of Egypt (Diodorus Siculus, Hist., I, 19, 4). The extensive harbour facilities and temple of Amun-Gereb, rediscovered by the Institut Européen d’Archéologie Sous-Marine (IEASM), provided the necessary infrastructure for the city’s role in the economic regulation of maritime trade. Located on Egypt’s coastal border, the port was a natural stop for merchant ships before or after a long sea voyage, a space where they could rest and give thanks to the gods.