The Pieria regional unit is bordered by Imathia to the north, Kozani to the west, and to the south and west by the region of Thessaly's regional unit Larissa. The Pierian Mountains lie to the west; the Thermaic Gulf lies to the east. It also has a valley by the GR-13. Most of the population live within the Olympian Riviera. The lowest point is the Thermiac Gulf and the highest point is Mount Olympus.