The Fort des Têtes is recognizable by its concentration of multi-story buildings with two or four-sided slate roofs. The barracks built on two or three levels are generally rectilinear - except for the one that occupies the old chapel of the fort and ends with a semi-cylindrical apse - and covered with two-sided roofs. At the entrance to the Fort des Têtes, the building of the Porte Royale rises on two levels topped by a four-sided roof.