Château de la Motte-aux-Bois, Medieval castle in Morbecque, France.

Château de la Motte-aux-Bois is a fortified residence in Morbecque featuring a strong stone front with a brick tower on one side and restored ancillary buildings arranged around its courtyard. The structure displays medieval defensive characteristics alongside later modifications and currently houses an aviation institute for training pilots and aircraft maintenance professionals.

Robert the Frisian built the fortress in 1075 in the Nieppe forest, where it was also called Ter Walle. In 1328 the duke of Normandy dismantled it after a siege at the Battle of Cassel. Marshal Turenne had the castle demolished in 1657, and in 1895 the last remains of the fortifications were pulled down before Baron Amaury de la Grange added a square tower.

The forest of Nieppe gave the castle its old name, Ter Walle. Yolande of Flanders, who died here in 1395, founded a chapel dedicated to Saint-Denis around 1381. Nearby stood the Trinitarian priory of Préavin, founded around 1396, a Marian pilgrimage site where Robert Gaguin studied around 1450.

The location sits within a wooded area and is best approached by car or on foot, as the surroundings are rural with limited public transport options. Visitors should check access conditions beforehand since the grounds remain in active institutional use, and arriving during off-peak hours or weekdays may offer better viewing opportunities.

Baron Amaury de la Grange, who bought the estate in 1895, had the last remains of the medieval fortification demolished and added a square tower. In 1962 his son gave the castle and its 100-hectare estate to the Institut aéronautique et école de pilotage Amaury de la Grange, which still trains pilots there.