To choose the best caption, I would need to know what the photo depicts. However, if the photo shows people at a church, then "Vamos a la iglesia los domingos." would be appropriate. If it depicts a swimming pool, then "Vamos a la piscina los domingos." would fit. For a nature scene, "Vamos al campo los domingos." would work, and for a park, "Vamos al parque los domingos." would be the best choice.
Please provide more information about the photo to determine the most suitable caption.