The ruins of Ten Duinen Abbey, just outside Koksijde (a short drive or bike ride from De Panne), are among the most historically significant medieval sites on the Belgian coast. Founded in the twelfth century in a hollow among the coastal dunes, the Cistercian abbey grew into a vast complex controlling estates across Flanders.
Today the site preserves extensive floor plans of the church, cloisters, and monastic buildings, excavated in the twentieth century and left uncovered so visitors can understand the scale of what was lost. A modern museum on the grounds provides context with archaeological finds, medieval manuscripts, and reconstructions.
The abbey museum is open throughout the year except Mondays. The ruins are most evocative in low light; visiting on an overcast day out of season gives the place an appropriate gravity. Combine with a visit to the Delvaux Museum nearby, which is also in Koksijde.