The most beautiful hidden tiles of the city, the head of the serial killer Lisbon preserved in formalin, the Kabbalistic principles of the south portal of the Jeronimos Monastery or the theory of the fifth Portuguese empire of which we find so many traces in the geography of the city, charming forgotten dead ends, the outstanding panoptic architecture of a former hospital, the impressive wax masks from the Dermatology Museum, a secret passage at the Avenida Palace Hotel, the mysterious abbey below Palacio Foz, the reason why the coat of arms of the Portugal is inclined at 17 ° on the facade of the Rossio station ... Far from the usual crowds and clichés, Lisbon still keeps well-hidden treasures that it reveals only to inhabitants and travellers who know how to think outside the box.