Built on a hill overlooking the Perfume River, 4km southwest of the Citadel, Thien Mu Pagoda is an icon of Vietnam and as potent a symbol of Hue as the Citadel. The 21m-high octagonal tower, Thap Phuoc Duyen, was constructed under the reign of Emperor Thieu Tri in 1844. Each of its seven storeys is dedicated to a manushi-buddha (a Buddha that appeared in human form).