Citadel of Diest
The Citadel of Diest [nl] is the only brick citadel left in Flanders. The citadel was built between 1845 and 1843 on the Allerheiligenberg. The construction of the Citadel was the dominant final piece in the transformation of Diest into a fortified city, as the city walls and gates had been built prior. The whole structure is purely geared towards military functionality, with the only embellishment being the bluestone gate in neoclassical style.
The citadel is located on the hills on the Demer. Major Laurillard-Fallot (1787-1842) was responsible for its design. The structure has the shape of a bastioned pentagon with sides of about 190 meters. The whole was surrounded by a dry moat and in front of the gate was a drawbridge. The citadel is located on a site of 28ha and the buildings themselves cover an area of 10,200 m².
Wikipedia