Architectural monuments preserved in the Turkmen SSR reflect all socio-historical epochs of human development. The era of antiquity is represented by the fortresses and palaces of Nisa; the building culture of more than a thousand years of feudalism is revealed in numerous castles, hillforts, caravanserais, mausoleums, madrassas and mosques preserved in Dahistan, Serakhs, Merv, Kunya Urgench and other centers of medieval civilization.