Getting around Barcelona

If you plan to stay in Barcelona for a couple of days, consider buying a 2-day travel card. This pass allows for unlimited travel on all trams, buses and metros for 48 consecutive hours and provide the cheapest way for visitors to explore the city (10 €). Passes can be purchased at any metro station or at any tourist information office. 3-day, 4-day and 5-day travel cards are also available.

http://www.tmb.net/en_US/barcelona/moute/targetes/targetes.jsp