The Citadel of Lille is a pentagonal citadel of the city wall of Lille, in France. It was built between 1667 and 1670. It hosts the Corps de réaction rapide France. Dubbed "Queen of the citadels" by Vauban, it is one of the most notable citadels designed by Vauban. It is remarkable for its size, the quality of the architecture, and the state of preservation today. Its various components have been classified as historic monuments in 1914, 1921 and 1934 respectively.