This abbey was founded by Benedictines in 1107 and became Cistercian in 1138. It was one of Western Europe's major abbeys under Abbot Elias van Koksijde around 1300 and was destroyed by Calvinists in 1566. The ruins still reveal the majestic lines of the abbey church. The museum displays the result of digs carried out since 1949, a model of the Medieval abbey and history, fauna and flora collections.