The Raval neighborhood has always been the poorest in the city, especially from Hospital Street to the sea. Today it welcomes people from all around the world.
You can start a tour of the neighborhood by having a coffee on the terrace of the Mendizabal bar (Junta de Comerç 2), a Barcelona’s classic. From there, take the Hospital Street and visit the Rubió i Lluch Gardens (Hospital 56). Here was the first hospital in Barcelona (here comes the name of the street), created to meet the great bubonic pest pandemic in the 14th century. It is worth visiting the building and having a drink on the terrace in the gardens.

Continue along Hospital Street until Rambla del Raval, a street built in the early 2000s. Here you can see the spirit of the neighborhood. You can then look for Calle Sant Pau to go to the Filmoteca (Salvador Seguí 1), a very nice public cinema. The Filmoteca’s bar is very nice.
Don’t go at night to some streets of this area: Robadors, Cera or Sant Ramon could be somehow dangerous at certain hours. With daylight there’s no problem. And the rest of the neighborhood is fine as well, we lived there for a while.
To finish, a couple of recommendations to eat in the area. The first is Bacaro (Jerusalem 6), a small authentic Italian restaurant. The second is Cañete (Unió 17), where you can try several traditional Spanish dishes very well prepared. In both places it is convenient to book in advance.
