The sea existing till the end of Oligocene was dotted with many islands in what is today the Balkan Peninsula area. At the very beginning of the Miocene this region became dry land, the Balkan Land, which was covered through time by lake systems of variable extent. During the Lower Miocene a succession of three lake systems spread not only over the Balkan Peninsula (comprising ex-Yugoslavia, NE Macedonia, SW and SE Bulgaria, and central Greece) but also over the northern parts of the Central and some of the Western Paratethys. Lacustrine environment ended shortly after the beginning of the Middle Miocene, when waters of the epicontinental Paratethys Sea covered the Balkan Land from the north. In this paper we do not consider any of the Upper Miocene and Pliocene lakes.