Žirmūnai's southernmost section, which lies on the bank of the River Neris opposite the Vilnius Castle Complex, was part of the settlement known as "Žvejai"; another part of that settlement is now located within the elderate of Šnipiškės. According to archaeological surveys from 2005, a fishing village may have been located here as early as the late 14th century, giving the area its name, literally, "Fishermen"; it was later settled by craftsmen and housed the Orthodox Church of St Barbara. During the 16th century, the only glass factory in the Grand Duchy of Lithuania was located in the suburb of "Žvejai". In 1563, after the construction of the first bridge over the River Neris (at the approximate location of today's Mindaugas Bridge), the suburb of "Žvejai" became an integral part of the city of Vilnius. During Tsarist rule in the 19th century, the name of "Žvejai" was superseded by that of "Piramont", originating from the small estate of Piramont in the area (now Kalvarijų 1). "Piramontskij" Alley can be seen in a 1904 map of Vilnius where today's "A. Juozapavičiaus" Street in the elderate of Šnipiškės is located, close to the boundary of Žirmūnai. The usage of "Piramont" as a placename gradually became limited to the southern part of "Žvejai".