St Janskerk is famed for its 70 magnificent stained-glass windows (16C). Founded in the 13C, the church was rebuilt three times following a series of fires and extended each time: it is the country's longest church (123m). This is a basilica with transepts from the late-Gothic period, crowned by wooden barrel vaults. Light floods into the plain interior through the large stained-glass windows that are set into the numerous pointed gables surrounding the church.