The boundaries which historians and geographers give to this province vary. In the systematic geography of Ptolemy the name is given to the extent of coast between the mouths of the Ludias and the Haliacmon rivers. Pieria was bounded on the West from the contiguous district of the Thessalian Perrhaebia by the great chain of Olympus. An offshoot from Olympus advances along the Pierian plain, in a North-west direction, as far as the ravine of the Haliacmon, where the mountains are separated by that chasm in the great eastern ridge of Northern Greece from the portion of it anciently called Bermius. The highest summit of the Pierian range called Pierus Mons and is a conspicuous object in all the country to the East. It would seem that there was a city called Pieria, which may be represented by a tumulus, overgrown with trees upon the extremity of the ridge of Andreotissa, where it ends in a point between Dium and Pydna, the other two chief cities of Pieria. Beyond Pydna was a considerable forest, called Pieria Silva, which may have furnished the Pierian pitch, which had such a high reputation. The road from Pella to Larissa in Thessaly passed through Pieria, and was probably the route which the consul Quintus Marcius Philippus pursued in the third and fourth years of the third Macedonian War (171 BC-168 BC).