The Casemates belong to the Monidal Heritage of UNESCO. The origins of the Pétrusse Casemates go back to the time when the Spaniards modernized medieval structures and built large bastions, such as the Beck, whose platform is occupied by the current Constitution Square.

But originally, this  fortification did not measure the current height.

The platform was located at the same height as the neighboring false-braye on the right (the terrace which was once reached by the grand staircase). For defense, this platform was surmounted by a horseman, a high masonry work serving as a location for a few cannons and whose parapet corresponded to the level of the current Boulevard Roosevelt. In 1673, the Spaniards raised the Ravelin (an old term for a demi-lune) du Pâté, intended to strengthen the Bastion Beck. This work is one of the rare fortifications in Luxembourg that has been largely preserved. Marshal de Vauban gave the works of Pétrusse their current form. In 1728-29, the Austrians built with the Bourbon Lock the “grand staircase” and in 1746, the casemates called the “Battery of Pétrusse”.

After the fortress was dismantled in 1867, they contented themselves with walling up the loopholes and closing most of the entrances, but a final honor had to be paid to the old ramparts.

The Société des Arquebusiers, the former Confrérie de Saint-Sébastien, founded in the 14th century, settled on the false braye on the right, from where it fired on the ditches of Fort Bourbon opposite. At the same time, an intelligent gardener took advantage of the galleries and batteries of Ravelin du Pâté to cultivate mushrooms. After the departure of the arquebusiers in 1903, the Pétrusse Casemates were completely closed.

Since 1933, they have been accessible to the general public.