Open house at Vondelkerk, Posthoornkerk, De Duif, and Oosterkerk. Free access. Volunteers will provide information about the history and architecture of the buildings. Other open houses: De Duif and Vondelkerk are open every third Sunday of the month from 13:00 to 16:00. Posthoornkerk and Oosterkerk are open every third Sunday of the month from 12:00 to 16:00. Bakenesserkerk is open every third Sunday of the month from 12:00 to 16:00. Check the culture agenda for the latest updates and exceptions.