One of the most important aspects of studying the ancient history of the Black Sea region in general and the northwestern Black Sea region in particular is to take into account the ancient geography of this region. Ancient authors have given us brief but very valuable descriptions of the Black Sea coast. Information about it was preserved in the works of Herodotus, Ps-Skylacus, P.Sky, Strabo, Meli, Pliny, Arrian, Ptolemy, the Anonymous author and other ancient historians and geographers. The sources give a general description of the region, indicate large rivers, estuaries, bays, islands, ancient cities, settlements, harbors, and note the location of local tribes. There are 17 settlements between the rivers Borissfen and Istra: the fortification of Alektor, the island of Borisfenida, the city of Odesa, the town of Otopeda, the harbor of Istrian, the harbor of Isakov, the city of Fisk, Nikonium, the extraordinary Tire, the island of Tiger, the Tower of Voptolema, the German village, the city of Khybrynka, the city of Kholnyaski, the city of Epopolia, Harpis, the Anti-Filov settlement.