Best if you tell us which resort, as accessibility to transport can vary depending on where you are staying

we have used the Train from a few resorts on the costa brava going into barcelona and they are very very good , an excellent service in my opinion. Never gone to Madrid and not sure how convenient it would be by train or coach, maybe your easy option would be to fly from either Barcelona or Gerona airport.

Lynne

Trains about an hour from Calella to Barcelona.