Like the Saint-Jacques Gate, the Gate of the Citadel known as the Clock Tower is an entrance châtelet dating from the beginning of the 13th century, composed of two almond-shaped towers framing a vaulted passage. The latter is surmounted by a guard room communicating with the parapet walk of the neighbouring walls, and giving access to the summit platform. In 1454, the platform was equipped with a bell ringing the hours (the square bell that houses it is more recent).