Sơn Tây Citadel is a historical fortress located in Sơn Tây, a town in Hà Nội Province, Vietnam. Built in the late 19th century during the French colonial period, it served as a military stronghold. The citadel features impressive stone walls and a unique architectural style that reflects both Vietnamese and French influences. Today, Sơn Tây Citadel is recognized as a national heritage site. It attracts visitors interested in Vietnam's history and architecture. The site offers a glimpse into the past, showcasing the strategic importance of the citadel in protecting the region during various conflicts.