Beautiful paintings. Definitely worth visiting. Arrive early in the day - later on they may ask for admission fee (to prevent from crowding up the church from tourism). Skip the tour.
Regardless of what Foursquare says, the church is closed on Mondays. We tried to visit on 3 March 2014 and we were informed by the guard they are closed on Mondays.
Linda demais por dentro, com várias pinturas originais (incluindo de Goya) e vitrais bem bonitos. A cúpula é linda, além de ser a 3ª maior do Cristianismo. Vale a pena visitar.