Q:  Where would you reccomend to exchange currency? Should I do it at the airport, is there a bank in Las Ramblas, or do the hotels offer this service?

A: There is currency exchange at Barcelona Airport. Barcelona airport also has cash machines where you can withdraw cash directly with your cash card.   Las Ramblas has dozens of banks that will undertake currency exchange for you. Many of the larger hotels also undertake currency exchange.  You may not get as good exhange rates at hotels or the airport than you would at a high street bank.