Piastów is a town in central Poland, near Warsaw, with 23,331 inhabitants (2006 est). It is situated in the Masovian Voivodship (since 1999); previously, it was in Warszawa Voivodship (1975-1998). With 4,050.5 persons/km², it is the second most densely populated city in Poland (after Świętochłowice) (...) (from Wikipedia)