Public transportation is the most convenient way to travel around Barcelona. You can use the T-10 ticket for €11.35, which covers 10 journeys, including transfers for up to 75 minutes. A taxi from the airport to the city center costs around €30, while a train ticket would cost €4.20 and take around 27 minutes.
If you have more time, you can visit Casa Batllo or Sagrada Familia for more Gaudi architecture experiences. If you have less time, you can choose either Park Guell or Camp Nou Stadium. Don't forget to try some local dishes like Patatas Bravas and Paella.
Barcelona has one main airport, Barcelona-El Prat Airport (BCN), which is located about 14 kilometers southwest of the city center. The airport has two terminals, connected by a shuttle bus that runs every 6-7 minutes. The journey from the airport to the city center takes around 30 minutes by train or taxi.