The fortified area around the hill, with its defence bastions, walls, walkways, tunnels, etc., is the result of different interventions conducted in the context of armed conflicts in modern and contemporary times. However, they are not the only defensive structures that the city of Lleida has known.
The Roman city of Ilerda and the Muslim Larida were already fortified. The fact that they were acropolis cities forced them to have a citadel atop the hill and walls that surrounded the town that extended down to the River Segre. The same would apply to medieval Lleida, where the wall with different towers and gates took advantage of the Andalusian structures and slightly enlarged them.
However, the impregnable appearance of the hill was evident during the second half of 15th century in the context of the civil war against John II, with great damage to all its defences. Thereafter, the need to improve the fortification would be imposed, a need that was quite evident with the advent of the modern era of heavy artillery in Europe.