The fortification of Cagayan de Oro is attributed to Fray Agustin de San Pedro OAR. The fort as Fray Agustin built it may have been a palisade reinforced with earth and stone redoubts. After successfully repelling Sultan Kudarat of Maguindanao, “el padre capitán” fortified northern Mindanao. Cagayan was the site of a fortification he built beside the church of Cagayan de Oro. This fort was part of a defensive line in northern Mindanao, which would include Iligan west of Cagayan de Oro. Iligan was under the Jesuits, who may have built Fuerza de San Francisco Xavier by the 16th century. Cagayan was under the Recollects following an agreed division of Mindanao into an eastern and western district, with the east falling under the Recollects and the west under the Jesuits. The diving line passed through Initao, west of Cagayan,
The Cagayan fort was apparently designed as a quadrilateral. Tradition has it that during a siege at the Cagayan fortification, the Virgin Mary appeared at the parapets and sent the Maguindanao forces retreating. An imaginative re-creation of the fort and the miraculous appearance of the Virgin has been painted for Xavier University’s Museo de Oro by museum artist Nonoy Estarte. In this painting the fort is depicted as a palisade.
At the turn of the century the fort was torn down by Spanish governor of Cagayan. A photograph of the fort, dated ca. 1890, is in the collection of Museo de Oro. A copy of the Museo photograph is in the photo archive of Filipinas Heritage Library (Photo ID AR00178). This photograph shows a fortification with whitewashed stone walls, so the fortification in the 1738 report of Valdes Tamon may have been rebuilt at a later time with more solid and permanent materials
Oral tradition claims that the stone walls of the fort encompassed present-day Gaston Park. A small wooden image of the Virgin, popularly called “Birhen sa Kota” is in the Museo de Oro. A reminder of the demolished fort, where the image was placed in niche on the fort’s wall, the statue was originally in the possession of Abp. James Hayes, who donated the image to the Museo.
The church of Cagayan was damaged during the war and greatly remodeled and improved by Abp. Hayes in the 1950s, recently the church, now a cathedral, was further remodeled. An atrial cross in front of the church is said to be standing at the same location where a cross was placed during the Spanish colonial period.