The military architecture is one of the most interesting constructive aspects of the 16th century in Alicante. During this period, the Berber pirates devastated the Mediterranean coasts. The defence of the territory was organized from the construction of watchtowers. The watchtowers mission was to alert the nearest workhouses to the continuous sieges. These towers were built next to the sea and had a military nature. In Alicante, in the rural area named as La Condomina, several fortified houses appeared scattered among the rural paths with their square or rectangular towers. They are known as Torres de la Huerta, and they had civil nature because these constructions were built next to hamlets and surrounded by walls that protected them. The enemy could be seen from the watchtowers on the coast; meanwhile those towers placed in the interior were used as refuge to the local inhabitants. A greater number of these last towers were built during the reign of Felipe II. This article focuses on the constructive aspects and original materials used in Rejas Tower, one of the most outstanding and best preserved towers in this territory. This building is an important exponent in the defensive architecture in Alicante during this period due to the construction techniques and original materials used.