As the population of the new Jordaan neighbourhood began to explode in the 17th century, the city decided to build a new church for its lower class protestant residents. Hendrick de Keyser, the illustrious designer of the nearby Westerkerk, was tasked to create the building and it was finally completed in1623 in all its odd octagonal glory. Inside the black gravestones that pave the floor have been polished smooth by centuries of foot traffic from its devoted parishioners. Although the interior is rather plain, and even the huge windows have only clear glass, the massive pipe organ is a sight to see.