One of the places of interest is the biggest Jewish cemetery in Europe, still preserved in its pre-war state on Bracka Street. Then you will head for Radegast railway station, once the departure point to the death camps in Chelmno and Auschwitz.
You will visit the areas of the former Litzmannstadt Ghetto, one of the most remarkable ghettos in Poland and which became known throughout the world because of the actions of Mordechai Chaim Rumkowski, the head of the Judenrat. You will not miss the only remaining synagogue in Lodz, surviving WW2 only because it was turned into a storehouse for salt. Nowadays it is open for Jewish religious services.
Finally you will visit Poznanski’s palace and, depending your interest and schedule, you will have the opportunity to visit the city museum.