The mission remains are not yet fully understood, but archeologists have determined how some structures were used. The eastern side of the main structure is believed to have been the first chapel, constructed shortly after the mission was established. The bell tower's architectural details have been lost, though it likely resembled a typical mission bell tower like the one at Mission Concepcion in San Antonio. A small structure along the wall may have served as a residence for native inhabitants, soldiers, or missionaries. A small room in the first chapel likely functioned as the priest's sacristy; in addition to introducing the Catholic faith to the native population, the priest oversaw all of the mission's administrative and financial affairs. Soldiers from nearby Presidio La Bahía guarded the south gate to protect the mission from threats.