Most of those found in lower altitude are the common Mediterranean and central European species. "Jankaea heldreichii", a plant relict of the Ice age, is of particular interest to botanists. The intense diversity of the landscape, the varying orientation of the slopes and their position in relation to the sea affect locally Olympus' climate and so a local microclimate prevails, combined with the geological background and the soil favor the growth of particular vegetation types and biotopes. Generally Olympus' northeast side is densely forested, as it receives the most rainfall, while the southwest one has significantly sparser vegetation.