The little, primitive fortress grow outside and around its walls, due to a gowing population in search for protection against the attacs of the enemy in time of war.
Because of the development of the town in the little plateau contiguous to the fortress and the growing number of those in search for defence, the borough became to small to shelter so many people in case of danger.
Afonso Sanches, son of king Afonso III, received from his father several lands in the place of da Vide. After some years, convinced by the power of weapons, he had to retourn this donations to his brother king Dinis.
Afonso Sanches started to repair the fortress and the construction of the town-walls that would surround the houses built by its walls.
As we have already mentioned, these works were continued by king Dinis and they were finished during the reign of his son king Afonso IV. To mark this event, a written memorial stone with granite surrounds and decorated with semi-spheres was placed above the main entrance.
After this period, the works carried out were just for repair of the primitive redoubt. Because was not big enough to tackle the demographic explosion, Manuel de Azevedo Fortes was obliged to begin, in 1710, the building of a new ring of walls to protect the houses that, at the time, already $nbsp;were widely spread.
The town-walls completed during the reign of Afonso IV have the shape of a long subrectangular stretching in the direction east /west.
Due to the relief, waving with the level curves, it goes up and down and sometimes on a straight line.
It do not matter where from we look down, everywhere seems if the wall is a natural extension of the cliffy slopes, crowned here and there with granite rocks, serious obstructions for everybody who came close.$nbsp;
The defensive walls evince various scars done by war machines: catapults, pierrer à boite, bombards and cannons.
Some of these scars were covered in a hurry, others could wait for later repair. It is possible to see that the reparations took place in distinct periods by the used techniques and the different types of mortar.