Ark Citadel (Arg-e Ali Shah) is located in Imam Khomeini Ave, Tabriz, Iran. Arg-e Ali Shah is also renowned as Ali Shah Mosque (Ali Shah Citadel). Although today it is only partially extant, the Ali Shah Mosque is believed to have been the largest brick structure ever built.It was built in the IlKhanid period (1318-1339) by Ali Shah, the Iranian Minister. Within the construction, the roof of the mausoleum collapsed and the construction was stopped afterwards.Centuries later, during different wars (1804-1911), 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 headquarter, a barrack for the troops, and a small palace was added as well to the original plan of the Arg.During the Pahlavi era, parts of the Ark which had been constructed in the 19th century by the Qajar dynasty, were destroyed. This destruction was with the aim of purifying the original Arg construction from later developments.

In 1990s and 2000s a great Feast was built next to the Arg castle. The superstructure of the feast undermines the architecture of Arg castle. Despite the regulations of the Iranian Organization for Cultural Heritages and several courts hearing, the construction of the new structure continued and accomplished.Today, the only part of the massive walls and the southern sanctuary of the mosque have remained. These walls in fact can be considered as the main elements of Ali Shah's mosque.