The Kleisoura canyon is part of the important road linking the Argolid plain and the Prosymna basin (Berbati). Research,starting in 1993 led to the location of about 30 caves and rock shelters, two of which were explored with trial trenches; later, in 1994 and 1995, a systematic excavation was carried out in the rock shelter no.1. The results of these investigations allow us to outline the evolution of the Prehistoric habitation during the last cold phase of the Glacial period (25.000-15,000 BC.), the Late Glacial (15,000-10,000 BC.) and the Early and Middle Holocene. This outcome therefore includes the Upper and Final Palaeolithic period, the Mesolithic period, as well as traces of the Middle and Late Neolithic, and ends with traces of the Bronze Age.