The Spanish Customs House, perhaps the oldest structure in Bay St. Louis, is believed to have been built by French colonist Hyacinth Caron in 1787, with the construction date based on an inscription in the brickwork. A two-and-a-half-story stuccoed brick building of Creole architectural influence, it originally included a two-tiered gallery on all four sides and three rooms on each floor connected by an exterior stair. It was destroyed by Hurricane Katrina in 2005.