Step by step a tunnel leads you down into a world of its own. Dark at first until the eyes had time to adjust. In the meantime you sense the humidity of the former cistern. While an ethereal sound fills the space, blue and white lights illuminate the Aljub de la Misericòrdia.  What feels like a secular cathedral actually used to be a water reservoir. For a long time, almost nobody knew about this hidden gem in the heart of Palma. And until today, a year after the thorough renovation and opening…