Polderhuis
The polder administration was part of the civic administration, so a room in the town hall was not surprising. The polder board was mainly concerned with what we now call water management: will the dykes hold, how do we control the water level. In 1925, a separate Polderhuis was built for the polder board, which at the time consisted of four district councils from Oostzaan and four from Oostzaandam. The stained-glass windows feature municipal coats of arms.