From Fira metro stop to Barcelona airport
To get to Barcelona airport from Hospitalet's Gran Via Fira, take the line 9 to the terminal of your choice, making sure you have the right metro ticket.

From the Fira to Barcelona city centre
If you have just assisted at one of the exhibitions at the Fira Gran Via in Hospitalet de Llobregat, and wish to go to the centre of Barcelona, take the line 9 towards Zona Universitaria and then change at Torrassa station to take the line 1 towards Fondo to the Catalunya stop to get out at the foot of the most popular square in the city as well as the Ramblas and the Passeig de Gracia.

From Mobile World Congress to Montjuic
From Fira to Fira; if you want to go from Hospitalet Fira to Montjuic Fira, don't take the line 9, get the line 8 which is on the other side of the complex.
The line 8 takes you to the foot of the Plaça Espanya and its Fira, as well as the Barcelona Olympic Games facilities. The Plaça Espanya metro station is also the gateway to the old bullring, Joan Miro Park, and a starting point for exploring Montjuic Hill, which hosts many of the city's must-see attractions.