A special place in the defensive system of ancient Philippopolis is occupied by the Eastern Gate complex - the main entrance to the city, impressive with its monumentality and well-preserved archaeological structures. It is located at the foot of the Three Hills and consists of a street 13.20 meters wide, equipped with sidewalks and colonnaded porticoes on both sides. The street is paved with large syenite slabs, preserved in their original form. This is the widest preserved Roman street discovered on Bulgarian territory. As early as the 2nd century AD, a gate with an honorary arch stood at this site. The gate has three entrances - one large central passage and two smaller ones for pedestrians. According to preserved inscriptions, its construction is dated to around 172 AD, during the reign of Emperor Marcus Aurelius. It is believed that military barracks were located on both sides of the street, forming a complex together with the gate itself. Between the buildings and the street stood free-standing marble columns. The monumental design of the Eastern Gate indicates that it served as the most representative entrance to the city.