Very few written sources have survived about the fortification of medieval Smolensk, and excavations of fortifications were carried out only a few times in the past. The materials of test pitting and observations of construction work are not a first-class source for solving the problems of establishing chronology and the reconstruction of the appearance and engineering of such structures. Both the data of written sources and the materials of archaeological research were considered in the past through the prism of an outdated concept, which viewed the ramparts as purposefully built mounds, on top of which palisades or hollow log cabins were placed. At the present stage, a different vision of ancient fortification has been developed: the ramparts are the ruins of earth-and-timber walls, which were chains of oak log cabins filled with soil. Only after the destruction of the wooden sheathing and the pouring out of the soil were earthen ridges-ramparts with the remnants of wooden log walls inside them formed. Within this framework, a new examination of the materials from the excavations of previous years in Smolensk shows that the structures discovered here fully correspond to this theory. The value of Smolensk artefacts also lies in the fact that the study covered the remains of the walls erected in the 16th century, which have not been an object of archaeological excavations in any other Russian city. However, that time, due to the spread of firearms, was the period of a rapid transition from medieval traditions of construction to new techniques aimed at countering cannon fire. Investigation by archaeological methods has established that the late medieval wall of Smolensk was created according to the norms of ancient Russian defense architecture, but written sources testify to the presence in these wooden walls of the “lower battle”, chambers for installing canons. Smolensk was the first case in Russia where the central part of the gateway in the wall of the 16th century was explored. The gateway was placed at the bottom of a natural hollow and equipped with drainage. The article also considers the issue of dating the construction of this wall with the involvement of the entire complex of written and archaeological sources, which allowed us to propose two versions of such a date: around the 1530s and mid-1580s.