At the courtyard of the Gravenkasteel (Castle of the Counts). This was originally a stronghold that was built by Count Baldwin I around the year 868.
It was rebuilt on the instructions of Philip van der Elzas, Count of Flanders by around 1180.

This was the seat of the county court of the Council of Flanders. Innumerable rooms and cellars were used as prisons.
Inside the counts' private quarters a museum of torture devices has been established.