ince medieval times, the most widespread type of fortification was the tower, alone or together with a small surrounding enclosure. It is the most elementary system of fortification of small villages which had their origin in a family clan. Watchtowers, such as those of the coast of Huelva, are a very special kind of tower, completely different from fortified ones, and whose only function was watchfulness. Watchtowers do not provide shelter and were not regular places of residence either.

Walls of cities and villages are the alternative fortification system in the kingdom of Castile, inherited from either the Hispanic-Roman cities or the cities founded and planned by muslims and christians in the Middle Ages.