A bastion is an angular structure projecting outward from the curtain wall of an artillery fortification. The fully developed bastion consists of two faces and two flanks with fire from the flanks being able to protect the curtain wall and also the adjacent bastions.  Bastion fortifications offered a greater degree of passive resistance and more scope for ranged defense in the age of gunpowder artillery compared with the medieval fortifications they replaced.
Santa Tecla also known as platform, is the youngest of all. By the very nature of the terrain, and the fact the better defended front cover, it was determined that its dimensions were smaller. This situation, which we could call rearguard, also gave rise to almost half of its space was occupied by a powder keg. It was stored all necessary for the functioning of the different pieces of artillery: fuzes, baits, different types of mecha, etc. It was also the load of explosive projectiles. This work has a cut in its Gorge with a parapetado wall and moat with two assorted to the main, one in each of the flanks and an access door to the stables in the middle of the Gorge.
In the early 1930s this old magazine, now disused, was reused as a canteen for troop: the so-called home of the soldier. This developed inside and was also created a picturesque garden, much to the taste of the time. It just is a Bank of design naturalistic, imitating branches, and a delicious wainscot tile, inspiration of hispano-Arabic. This last detail we immediately moved to colonial North Africa environments and gives us an image of the influence that for many soldiers of the time was staying in the protectorate of Morocco.