Tarczyn – town in Mazovia Region, Piaseczno Poviat, seat of Tarczyn commune. Since 1954 seat of Komorniki commune. In 1975 – 1998 the town belonged to Warsaw voivodship. It was a spiritual town. The town is upon Tarczynka river, small Vistula inlet, left inlet of Jeziorka River. According to December 31, 2012 data, town had 4121 residents. nternational route E-77 goes through the town, just like train line No 12 Lukow – Skierniewice. There is an opened gauge train station of the Grojecka Kolej Dojazdowa in Tarczyn.