The current castle dates to 1180 and was built by Philip of Alsace (1143–1191) on the site of the older fortification. It may have been inspired by crusader castles witnessed by Philip during the Second Crusade. As well a protective citadel, the Gravensteen was intended to intimidate the burghers of Ghent who often challenged the counts' authority. It incorporates a large central donjon, a residence and various smaller buildings. These are surrounded by a fortified, oval-shaped enceinte lined with 24 small échauguettes. It also has a sizeable moat, fed with water from the Lys.