In ancient geography, Paeonia (or Paionia) was the land of the Paeonians. The exact original boundaries of Paeonia, like the early history of its inhabitants, are very obscure, but they lay in the region of Thrace. In the time of Classical Greece, Paeonia might have later included the whole Vardar River valley and the surrounding areas, in what is now a narrow strip along the northern part of the Greek region of Macedonia, most of the present-day Republic of Macedonia, and a small part of southwestern Bulgaria. It was located immediately north of ancient Macedonia (which roughly corresponds to the modern Greek region of Macedonia) and to the south-east of Dardania (roughly corresponding to modern-day Kosovo). In the east, were Thracians; and in the west, the Illyrians. From Dardania, Paeonia was separated by the mountains through which the Axius passes from the field of Scupi to the valley of Bylazora (Veles).