Otwock is a city in the Masovian Voivodship in east-central Poland, some 23 kilometres southeast of Warsaw, with 44,635 inhabitants. Otwock …Otwock is a city in the Masovian Voivodship in east-central Poland, some 23 kilometres southeast of Warsaw, with 44,635 inhabitants. Otwock is a part of the Warsaw metropolitan area. It is situated on the right bank of Vistula River below the mouth of Świder River. Otwock is home to a unique architectural style called Świdermajer.