Fort Leopold was built between 1841 and 1845. It is dug into the southern slope of the Lazarijberg (hill), about 400 metres outside the city. Thanks to it remarkable tower-shaped construction, it is possible to fire in all directions. The fort had a dual purpose. On the one hand, preventing the enemy from occupying the plateau located directly in front, an ideal spot to shoot at the city. And on the other hand, to protect the northern city front line by bombarding the enemy from the rear. Access to the fort was protected by means of a wide and deep dry canal. On top of the fort there are two earthen battle platforms and in the direction of the city there are in turn brick batteries.
During the First World War, the Germans used the fort as storage and for shorter periods, as sleeping quarters. After the war, a Frenchman started a mushroom nursery there and an orchard was planted on the surrounding hillside. During the Second World War, once again the occupiers used it as storage. Today Fort Leopold is empty.