The expansion tower, or water tower, is the tallest, most visible structure of Jewish Suburbia. It contains a cistern at the top that collected rainwater for the pools of the mikvah (ritual bath) and also regulated the pressure for the mikvah’s water and heating systems. Rainwater from the cistern was delivered to the ritual pools when the flow of water from the nearby millstream — the mikvah’sprimary source of water — was reduced. The use of such natural water sources for a mikvah is required by Jewish law. After World War II and the Holocaust, the once-thriving Jewish community in Bardejov nearly disappeared. In 1950, a small ritual pool was built in the cellar of the water tower to serve the needs of Bardejov’s few surviving Jewish residents. It was used until the demise of the Jewish community. The expansion tower is a cultural monument listed under the number 1789/2 in the Central Register of the Cultural Monuments of the Slovak Republic.