The beginning of this fortification is attributed to “El padre capitan” Fray Agustin de San Pedro, OAR who is reported to have built a fort in 1626; this was three years after the Recollects had established a mission in the area. However, the friar’s fortification was apparently a palisade. If there were a more permanent structure built is uncertain, but whatever be the case by the first quarter of the 18th century Fray Agustin’s fort was in bad state and had been abandoned. Because of Taytay’s close proximity to Borneo and in the track of merchant ships under other Europeans and the vessels of the seafaring pirates Gov. Gen. Fernando Manuel de Bustillo was prompted to rebuild the fort. He appointed Fernando Vélez de Arce as the castle chief because of his expertise in building fortifications learned at the public academy of Barcelona.
The successor of Bustillo in 1725, the Marques de Torrecampo reported that Taytay was fortified by a palisade and moved that stone structure be built in response to the request of the alcalde mayor of Calamianes who had called together a council of war. In October 1726, work had progressed such that the wall facing the town was completed. The castle master Juan Antonio de la Torre opined that it was necessary to demolish the redoubt called “la retirada” and suggested that a small structure or garita be built at the shore as a guide and protection for ships.
Five years later, the new alcalde mayor Benito Llanes y Cienfuegos reported that the fortification was on a rock but was indefensible as it was of poor quality material. Furthermore, he suggested that the fortification be built elsewhere rather than waste resources on repairs. He also suggested rebuilding the demolished redoubt “la reitrada.” In response, the central government sent the engineer Tomás de Castro to survey the area and submit his recommendations. De Castro replied that building a new fort of a much better and more adequate design was the preferred option. However, he was instructed that before such an undertaking to do some repairs on the fort (DT 1959:375-78).
This was apparently done, because in the fort’s plan as it appears in the 1738 Valdes Tamon report, parts are already indicated as being made of stone, some parts were still made of timber and others were planned. It seems that de Castro’s recommendation to build a completely new structure was not followed or rather that he was ordered to continue the reconstruction because a memorial stone on the inner side of the curtain wall indicates that de Castro was responsible for rebuilding the Taytay fort.
Described as a fuerza, Santa Isabel is built over a rock beside the sea. Planned as an irregular quadrilateral, whose perimeter followed the contour of the rock on which it is built, the fort has a seaward side curtain wall is arched rather than straight. Bastions are found at each corner of the irregular plan. Garitas are strategically located. A ruined chapel is in the center of the plan. Some below ground structures are visible but whose functions are uncertain. They may be the structures described in the 1738 report as storehouses. Despite being well-built the structure was vulnerable from attack, mounted on a nearby hill which opened to an unobstructed view of the fort.
Landor (1904: 111-112) describes Taytay and identifies the bellow ground structures as “dungeons,” he may be mistaken. Landor writes:
“The fort, which could accommodate six or seven hundred soldiers, was constructed on a high rock projecting into the sea and connected with the land by an artificial causeway. There was a passage with steps, and an incline by which the summit of the church could be reached some thirty-five or forty feet above the sea-level. By the side of this incline were two dungeons, now roofless. In former times these dungeons had only one small aperture to give light and air to both chambers. On the opposite (east) side of the entrance-gate was a large cistern with a fountain at the lower portion.The fort was one of the finest on Palawan Island, and had four bastions, those overlooking the sea to the north being semicircular, whereas the other two were angular. For its day it possessed some powerful iron artillery, such as one long five-inch piece dated 1812, and two four-inch (1823) cannon. A great number of one-pound bullets were used as mitraille in the big guns; possibly smaller guns were (page 112) in those times mounted upon the wall; or maybe it was ammunition fired at the fort by the Moro lantacas (brass cannon) in some attacks.The inside of the fort was at a slope, the north part being filled up to within five feet of the top of the wall. The two east turrets were reached by an incline, and a path was built all around the top of the castellated wall. The actual stone outer wall was no more than thirty inches wide, but it was filled with earth and thus made of great strength. The only building inside, which was formerly a chapel with two bamboo annexes, is now used as barracks for the constabulary force of seventeen men. The fort measures some forty paces square, and its walls was about forty-two feet high and vertical, except corner bastions at a slant, with a cornichon twenty feet above the ground all round.”