The First Missionary Church, located at the center of town, is the oldest and largest building in Cabeza del Dragón, originally constructed by Spanish missionaries who first settled the area. The church has since gone through numerous renovations, although much of its original architecture has been preserved. The main doors open directly into a high-ceilinged interior area, primarily filled with two columns of pews. There are six stained glass windows flanking the pews three to a side, with a seventh larger window depicting the crucifixion of Christ located behind a fancifully-carved pulpit and above an ancient organ that despite the outward appearance of its old pipes is still capable of producing some bars. Through a door situated behind the main pulpit and alongside the organ is the priests' quarters, which is made up of a small combined kitchen and living area, study, and bedroom. There are many books lining the shelves of a bookcase, but there are gaps and disturbed dust where some texts have been removed.