Mission San Luis Obispo is different from all the other' missions' because it is one of the smallest and has a unique design. The design has both belfry (a bell tower) and a vestibule, which is an entrance hall between the outer door and the interior of a building. These are not found on any of the other California missions. The main nave (the long entrance part of the church) is long and narrow. At San Luis Obispo there is a secondary nave that is the same size and at the right of the altar. This is the only "L"-shaped mission church. Windows around the courtyard have round pillars with square opening, unlike the arches of other missions. San Luis Obispo is painted white and is surrounded by gardens, wine vineyards, and a fountain.