Gdask is a city in northern Poland on the Baltic coast. Gdask is the capital and largest city in the Pomeranian Voivodeship, as well as the most important city in the geographical region of Pomerania, with a population of 470,805. It is Poland's main seaport and the country's fourt… Gdask is a city in northern Poland on the Baltic coast. Gdask is the capital and largest city in the Pomeranian Voivodeship, as well as the most important city in the geographical region of Pomerania, with a population of 470,805. It is Poland's main seaport and the country's fourth most populous metropolitan area.