Linao has disappeared entirely in modern maps, hence the location of Linao is disputed. The latest cartographic evidence available is found in a publication of the Manila Observatory, José Algue. 1900. Atlas of the Philippines (Washington: Government Printing Office). The data for the atlas was gathered prior to 1900 in fact it bore a Spanish title (See citation below). This map locates Linao between Veruela and Talacogon. It also indicates that there were four small lakes in the area, the fourth being Laguna de Linao. No such lakes exist today, however, the areas marked as lakes in the 1900 map of Mindanao are within the approximate boundaries of the Agusan wetland or marsh. These wetlands flood annually during the rainy season between July and October and when the floods recede can leave shallow lakes. Perhaps, the cartographers of the Manila Observatory gathered data after the annual flooding, hence the designation, “laguna.” Thus, the townsite of Linao is uncertain. It is said to be near New Era, a barrio of the Municipality of Bunawan. There are no remains of the fort, probably destroyed by the annual inundation of the Agusan marsh because the fort was built of perishable material—tree trunks and most likely stone and earth embankments. The only visual evidence we have of the fortification is in Valdes Tamon’s 1738 report where the quadrilateral plan of the fort is evident and where the material it is made of is indicated by small circles delineating the fort’s perimeter.
Delgado describes the fort as “estacada,” i.e., a palisade. Despite its humble appearance, this quadrilateral structure was the lynchpin of Agustin de San Pedro OAR’s defense network. Here he organized and trained Manobos as a fighting force against the Maguindanao. The fort was already standing in the 1680s. As one of the few inland fortification it the Philippines its purposes was the of the Christianized and colonized tribes against non-colonized tribes. During Fray Agustin’s time it was the training center for a militia of Manobo converts and protected the frontier of the Recollect missions in Agusan.