The capital’s palace complexes of the 6th–4th-century BCE Achaemenid Iran in Pasargadae, Susa and Persepolis embodied the principle of a synthesis of arts, in which architecture and sculpture, as well as the landscape environment, were organically combined. A special type of Iranian regular garden — a paradise — emerged in the era of the Achaemenids and its remains were excavated by archaeologists in the center of the palace complex in Pasargadae. The analysis of ancient texts (the works by Xenophon and Lucius Flavius Arrian) reveals the specifics of ancient Persian gardens-paradises and hunting parks, their various categories, organizational features and semantics of the palace garden. The study of cuneiform tablets from the “Fortification” and “Treasury” archives of Persepolis also provides valuable data on the hiring of special workers who cared for the royal gardens. Additionally, the Elamite cuneiform tablets from Persepolis evidence the existence of home gardens (“partetaš”) that, being predominantly agricultural, markedly differed from the paradises. The examination of the extant stone irrigation system of the royal paradise in Pasargadae reveals a strict geometric layout of the Achaemenid gardens with intersecting alleys that create a four-part garden structure. Subsequently, Iranian landscape-gardening art will take this composition as the basis of the Persian four-part garden (“chahar bagh”). The presence of compact park pavilions brings the royal paradise of Pasargadae closer to the earlier Assyrian gardens in Khorsabad and Nineveh in the late 8th–7th centuries BCE. In the classical Achaemenid palace complexes in Susa and Persepolis, landscape-gardening art loose its significance and supplemented architecture. Due to this fact, the royal gardens of the Achaemenids in the 5th– 4th centuries BCE were more compact and intimate. In this regard, the author considers the relevant issue of localization of the palace gardens in Susa and Persepolis. He explores the problems of typology and reconstruction of landscapegardening art in Achaemenid Iran on the basis of all the collected archaeological data and written sources.