This is one of two fortifications recently discovered by Cheyenne Morrison on the island of Linapacan. There are two structures, a lower and an higher fortification or bastion built unto the limestone hill beside the town of San Miguel, the principal town of Linapacan. The structure is overgrown by vegetation and straggler figs. Further study is needed to determine if this or the other fort at Caseladan is the one that is described in the 1738 Valdes Tamon report, where the fortification is drawn as a cluster of buildings surrounded by a perimeter wall that hugs the crest of a hill.
If this the structures at San Miguel are the ones cited by Valdes Tamon, then this gives an indication when the fortification was constructed, otherwise there is very little data on its history.
Landor (1904: 100-101) adds to our conundrum when he describes Linapacan because it does not correspond to any of the ruins discovered recently
“A mile or so farther we arrived at the town—about half a dozen huts among cocoa-nuts palms, scattered on the side of the hill, upon which an ancient Spanish stone fort overlooked the western bay.It was pentagonal in shape, with two angular bastions and three semicircular ones, with an inner area of 600 square feet containing a humble nipa church in a dilapidated condition, a shelter with three bronze bells, a rickety iron cannon on wheels—and some iron bullets for ammunition. There was all there was to the fort. The only noticeable portion of this of this structure was a vaulted door with a Spanish coat-of-arms elaborately and most artistically carved in stone, with graceful leaf ornamentations all around it. Seen from the outside, the wall of the fort looked much stronger than it really was, but where crumbling down from age—especially on its south and east sides—its flimsiness was apparent.” (Compare this description with the details on the other fortification discovered at Barangay Caseladan, Linapacan)