Start Arc de Triumf
Run northeast on Avinguda Vilanova
Run through park and past soccerfield until you get to Avinguda Meridiana where you head North
Head into roundabout at Glories going East
Head northeast on Avinguda Diagonal (past Torre Agbar)
At the roundabout (very end) at the Fórum take sharp right heading southwest on Passeig del Taulat
Take left on Carrer Josep Pla heading southwest
Run southest on beachfront along Passeig Maritim all the way to the Barceloneta
At Placa de Mar take right heading northwest on Passeig de Juan Borbon right by the port of Barcelona
Run through to Pla del Palau then take right and head northeast on Avinguda del Marques de l'Argentera until At parque de la ciutadela run to roundabout and then head northwest and you will see Arc de Triumf right ahead to finish.
Great and most scenic run with fantastic views of Barcelona is along the Carretera de les Aigües. Great place to start is by the funicular that goes up to the Tibidabo amusement park along the Carrer de Manuel Arnús. Up to 16K/10Miles.