Ciechanów is a city in north-central Poland, seat of the Ciechanów County in the Masovian Voivodeship. From 1975 to 1998, it was the capital o…Ciechanów is a city in north-central Poland, seat of the Ciechanów County in the Masovian Voivodeship. From 1975 to 1998, it was the capital of the Ciechanów Voivodeship. As of December 2021, it has a population of 43,495.