This monograph provides the first comprehensive, critical edition and detailed architectural analysis of three major temples closing the northwestern side of the Old Forum (Forum Vetus) at Leptis Magna. Excavated in the 1930s, these pivotal first-century BCE to first-century CE cult buildings had remained virtually unpublished, leading to persistent typological and planimetric misconceptions. Combining meticulous site surveys, structural catalogs, and architectural reconstructions, the volume elucidates the construction phases, decorative programs, and spatial development of the complex. Special focus is given to the Western Temple—traditionally attributed to Liber Pater—as well as the Temple of Rome and Augustus and the Temple of Hercules-Milk'ashtart. Ultimately, the study highlights a unique synthesis of Punic technical traditions, local materials, Hellenistic-Alexandrian stylistic influences, and imported Italic-Roman Augustan models, offering fundamental insights into the urban and architectural transformation of Leptis Magna as it integrated into the Roman Empire.