on Santa Rosa Island. Fort San Carlos de Austria The principal structure of the presidio was the Fort San Carlos de Austria, measuring 100 by 100 varas (the length of a vara varied, but was generally somewhat less than a metre). The walls of the fort were three varas high. The fort was surrounded by a deep moat. The walls of the fort were originally built of pine logs laid horizontally against upright posts, with the space between the inner and outer walls filled with sand. The humid climate and constant contact with sand quickly rotted the logs, and by 1707 most of the fort walls had been replaced by vertical logs. The settlement was struck by several hurricanes in the two decades of its existence, eroding the bluff below the fort and requiring shoring up of the structure. The wall on the south side of the fort, closest to the water, was eventually rebuilt behind its original position, distorting the symmetry of the fort. Structures inside the fort were a church, hospital, warehouse, governor's house, and three barracks, one each for officers, soldiers, and convict laborers. As there was no local source of stone suitable for building, and no brick kilns, all of the structures were built of wood. The walls and roofs of the structures were at first made of palmetto thatch. Lead-sheeting or shingle roofs and plank walls were added later to the more important buildings. Some of the buildings had solid floors, others had dirt floors. The site of Santa Maria de Galve has been investigated by archaeologists with the University of West Florida. Notes References External links Secret Exchange: Alternative Economies of Presidios Santa Mariá de Galve and Isla de Santa Rosa Pensacola, Florida Spanish forts in the United States Colonial forts in Florida Forts in Florida Spanish Florida Unreferenced Florida articles 1698 establishments in the Spanish Empire