Barcelona Metro line 6

Line 6, coloured navy blue, (currently known as Plaça Catalunya - Sarrià (?)) is the name of a metro-like commuter train service in Barcelona operated by FGC, and part of the ATM fare-integrated transport system. It links Plaça Catalunya, the city centre, with Sarrià-Sant Gervasi. This Barcelona Metro and Metro del Vallès line shares three stations with FGC L7.
Overview.
Prior to the "integration" with the TMB network, L6 covered as an underground commuter train line the distance from downtown Barcelona to Sarrià, pretty much the same as nowadays. It has its origins in 1876, with the Barcelona-Sarrià train. It's going to be extended towards Sant Boi, through Hospital Sant Joan de Déu.