Huế is a city in central Vietnam that was the seat of Nguyen Dynasty emperors and the national capital from 1802 to 1945. A major attraction is its vast, 19th-century Đại Nội Citadel, surrounded by a moat and thick stone walls. It encompasses the Imperial City, with palaces and shrines; the Forbidden Purple City (Tử cấm thành), once the emperor’s home; and a replica of the Royal Theater.