It had its own oven, fireplace and well, so that it could resist any attack. The system of defence is really impressive, it was impossible to penetrate the Cité passing through this tower.
The tower is square-shaped, and the gate giving access to the streets of the Cité is not in the axis of the way. It means that an enemy arriving in front of the tower was forced to advance following to the walls. His right flank was not protected by a shield, so he was very vulnerable.
Two series of obstacles (murder holes perfectly adapted to crossbow archery, hoardings, a heavy portcullis, and a right angled passage under the tower) made it impossible to get into the Cité. But why did the architect designed a angled passage ? Just because the enemy could not stand back enough and this made the use of a battering ram very difficult !
Oh, and not to forget the crenellation on the top of the tower !
This section of the fortifications was one of the weakest of the Cité. Viscount Trencavel knew it very well, when he tried to reconquer Carcassonne in 1240.
He decided to attack the walls at this place, where still remained the old Gallo-roman towers. They were already 1000 years old and in bad conditions. One of them collapsed and is still visible at the foot of the Mipadre Tower.
The kings of France never forgot the danger and strenghened the walls. They completed the defence system, as the same time as they erected the outer walls.
Nowadays, no danger ! Everyone can get into the Cité passing under the vaults of Saint Nazaire Tower. Then the visitor face the magnificent gothic choir of Saint Nazaire Basilica, Radulphe's Chapel and the Grand Theatre on the left.