Standing in isolation, situated on the borders of Thessaly and Macedonia in northern Greece, it is one of the most interesting botanical localities of the Balkans. The combination of long geographical isolation, an unusual range of climatical conditions, situated close to the sea and the meeting of Mediterranean and central European floras has resulted in a unique vegetation. Its a major refuge for some of the most exciting ancient endemic species of Europe. 23 unique species are found in this relatively small area and all being exclusively Balkan species. Mytikas summit (2918m) is the second highest in the Balkans. The summits of Olympos form a cone which has a diameter of about 20km, dissected by deep valleys. Like the wide Enipeus valley in the east and the narrower Papa Rema and Xerolakki ravines in the north. The eastern and northern slopes receive most moisture and have often a forest vegetation. Species of the alpine and upper montane zones, however, descend far below their normal range in these protected valleys. Olympos ia almost exclusively limestone, folded in the summit area and weathered into extensive screes in much of the alpine zone. The limestone is very porous, and although there is quite an amount of precipitation, the alpine area becomes very dry in summer.