We present here the results of three underwater excavation campaigns conducted between 1984 and 1986 on the harbour of Amathus, Cyprus, an exceptional monument of military architecture from the Early Hellenistic era. After a description of the twenty sondages undertaken along the moles, there follows a nomenclature of the blocks employed in the construction, their modules, the typology of bosses for hoisting and placing by a vertical boom crane, which...