The northern fortress gate of Abritus Late Antiquity fortress was located right at the center of the northern fortress wall and was flanked and protected by two U-shaped towers. The gate had rectangular design and was approached from the east – west. It was closed with two doors that formed a rectangular room – propugnaculum. The external door was descended from an upper second floor above the propugnaculum. The internal door was a two-winged wooden one and was probably cased by iron nails or metal plates that protected it from being cut to pieces. From the inside it was barred with thick wooden beams. Doors were closed in the evening and opened in the morning in order to secure the safety of citizens. It was guarded by soldiers who lived in barracks on the internal side of the fortress wall in close vicinity to the east of the gate. In case of attack the doors were closed and barred and the soldiers who guarded the gate took a defensive line along the two towers on both sides of the gate and behind the crenels of the fortress wall. Enemies were attacked with spears and arrows from the fortress wall and the nearby towers. In case the external descending door was broken, attackers found themselves in the propugnaculum in front of the internal two-winged door. There they were attacked with javelins and arrows and were poured over with hot water or heated oil or tar through openings at the floor of the room above the propugnaculum. In case the enemy broke through the inside door the last attempts at resistance came from the height of the fortress wall and the nearby towers, as well as from the streets in the interior of city. In the 6^th century probably because of shortage of people to defend the northern fortress gate of Abritus, it was blocked up: its passage was blocked with a thick stone wall and the gate ceased to function.