It cannot be stressed enough that newcomers to Barcelona must be on their guard. Petty theft is a problem in the city centre, on public transport and around main sights. Report thefts to the Guàrdia Urbana office at La Rambla 43. You are unlikely to recover your goods but you will need to make this formal denuncia (police report) for insurance purposes. To avoid endless queues at the comisaría (police station), you can make the report by phone (902 102112, in various languages). The following day go to the station of your choice to pick up and sign the report (the most central are the offices at La Rambla 43, Carrer Noude la Rambla 76 in El Raval, and the one in the metro station at Plaça Catalunya).