In 1888 the defeated Nguyen Dynasty surrendered the Hanoi Citadel to the French colonialists. Hanoi's Watchtower is located in the grounds of the Army MuseumHanoi became a colonial city 66 years until the French were expelled in 1954. During their occupancy, the colonists broke down the walls of Citadel and destroyed most of the buildings inside. The old Watchtower remains, and offers an excellent view of the whole complex.