In the course of the extensive survey of Sikyonia (1996-2002) by Yannis Lolos, more than 250 archaeological sites were recorded and mapped, including settlements, forts and watch/signal towers, roads, sanctuaries, quarries, aqueducts and cisterns, terracing walls, and other types of remains. Out of the 250 archaeological sites that we have mapped and examined in Sikyonia, we identified 148 as representing areas of habitation, with the earliest going back to the Neolithic period and the latest to the 19th century. We observed a certain concentration of prehistoric sites in proximity to the coastal plain (10 out of the 18 sites of this period), where also lies the most important prehistoric settlement site of Sikyonia that we have recorded, namely Litharakia of Krines, with a ceramic surface scatter of ca. 3 ha and an occupation from the Neolithic to the Geometric period. Habitation in Sikyonia followed a rising course from the 6th millennium to the Late Helladic period, and from the Geometric to the Classical period, where it reached its peak. The Classical period saw the appearance of the largest settlements outside the city (in 12 of those we observed a surface material scatter of over 2 ha), but also a multitude of smaller settlements (scattered over an area between 0.1 and 0.8 ha) which probably represent isolated farmsteads. For the satisfaction of the vital needs of the population, people have now started cultivating even marginal areas, semi-mountainous and usually lying on a slope, and attempted to improve their fertility by constructing retaining walls and other infrastructure works. In later Hellenistic, and less so in Roman times, we witness a shrinkage of settlement sites in the chora of Sikyonia. Recovery will come in Late Roman times, a phenomenon witnessed also in other areas of the Greek world. During this period we observed a tendency for medium and large sites with a corresponding reduction in the number of smaller sites, which suggests a growing preference for communal living. In addition, churches and monasteries now appear in the countryside, a tendency continuing during the Byzantine and post-Byzantine period, with the best example being that of the monastery of Lechova on mount Vesiza. The reduction of the rural settlement sites in Hellenistic and Roman times may be due to a general demographic crisis or (and) to the concentration of the population in the refounded city – the plateau of Vasiliko. The location and mapping of the visible segments of the ancient walls of Sikyon showed that the entire plateau, ca. 230 ha of surface, was intramuros. Data The data in this collection is spatial data collected and created from the project. It is all in GML format which can be used in most GIS applications.