Arg of Tabriz (, also known as Arg Alishah, Arg-e Alishah, Arch of Alishah, Arg Citadel, and Masjid Ali-Shāh), is the remnants of a large acropolis fortification (whence the metathetic name or plus ) and city wall in downtown Tabriz, Iran. Its structure is visible from far distances in downtown Tabriz, if not blocked by the newly erected highrise buildings. The structure was initially a compound, containing a great vaulted mosque, adjoining prayer halls and libraries, a vast courtyard containing a huge reflecting pool, and a mausoleum—all surrounded by a containing wall. It was built in 14th century during the Ilkhanate era. The point of pride for the building was that its vaulted ayvan was larger than the famous historic vault of Khosrows/Kisra or the Taq Kisra at Ctesiphon/Mada'in. However, with the sudden death of the governor of the city and with some construction complications in constructing a roofed building without pillar for such a huge complex, the mausoleum structure remained incomplete. In the 19th century with the rise of tensions between Iran and Russia the structure rapidly turned into the city's fort and additional military installations such as a barracks and cannon foundry were added to the original structure. During the twentieth century the military installations were removed from original construction and the surrounding of the ark turned into a park. In the late twentieth century a big mosque was built next to the citadel. History The original construction was made between 1318 and 1339, during the Ilkhanate. During the construction, the main barrel vault collapsed and the construction was stopped afterward. An earthquake in 1641 severely damaged and collapsed the monument. Centuries later, between the eruption of the Russo-Persian War, 1804-1813, and the Russo-Persian War (1826-1828), the compound was quickly reconstructed as a military compound. During the reconstruction of the Arg compound, a foundry factory for the manufacturing of cannons for the Iranian Army was built as well as a military headquarters, a barrack for the troops, and a small palace. Samson Makintsev (better known as Samson Khan) a Qajar Iranian general of Russian origin, lived inside the citadel for years together with his wife, the daughter of Prince Aleksandre of Georgia. Shelling of Arg by Russian troops, 1911 During the Russian invasion of Tabriz in 1911, the Russians shelled the Arg in initial attacks. Once they captured the city, they used the Arg as a central command