Barcelona International Airport (IATA: BCN, ICAO: LEBL), also known as El Prat, is a major transport hub and fields flights from all over Europe and beyond. There are three terminals, A, B and C, all within fairly easy walking distance of each other. A giant new south terminal is expected to open in 2009 or so.
The airport is only about 10 km away from the city center. Taxis are supposed to use a zone chart for trips into the city, but rarely do, and you can expect to pay up to €25. A cheaper and often faster option is the regular RENFE suburban train to Sants train station, which takes about 15 minutes. A single ticket is about €2.20, but an under-advertised fact is that you can use the T-10 ticket (€6.90 for ten trips, including all bus and metro transfers made within 75 minutes) instead. You can buy a T-10 from the ticket vending machine at the airport station.
Alternatively, the Aerobús A1 line stops outside all terminal buildings and travels along Gran Via to Plaça Catalunya. Buses depart every 6-9 minutes, the trip takes 20-30 minutes and costs €3.90 one-way. Aerobuses stop running at midnight, but you can catch a Nit Bus night bus service instead.
Some low-cost carriers, notably Ryanair, use the airports in Girona, nearly 100km to the north, or Reus, around the same distance to the south, instead. The Barcelona Bus service runs a shuttle bus from Estació del Nord in Barcelona to Girona Airport and this ties in with various flight times. A one-way ticket costs €12 and a return ticket costs €21. The journey takes approximately one hour and ten minutes. For Reus airport, the easiest way is to take the train from Barcelona Sants station to Reus and then the local bus to the airport. The train costs €6.45 and then the bus costs €2. This takes roughly an hour and a half.
By Rail
Several trains per day (including overnight hotel trains) from other parts of Europe (via France) are regular & reliable.
The long-delayed AVE high-speed train line is finally expected to reach Sant Joan Despí station, on the outskirts of Barcelona, by the end of 2007. Travel time from Madrid is expected to be around 3 hours, compared to 5 hours by normal train.
By Sea
You can arrive to Barcelona by boat from the Balearic islands, from Genoa and from Rome.