runs between Barajas terminal T4 and Zaragoza every 2-3 hours (3h45 trip, single/return: €15/€26). If you are in terminals T1 T2 or T3, take the free airport bus shuttle to terminal T4. The bus to Zaragoza stops in the same place as the airport shuttle. Yes, there are no ticket counters, information posts, or timetables, but place yourself with your back towards the T4 terminal exit, look at your right and you will see the ticket vending machine of ALSA.
From Barcelona Airport: The easiest way is to take the half-hourly RENFE C-10 suburban train to Barcelona Sants (20 minutes, €2.20), and then take the high speed train AVE to Zaragoza (1h45, around €60). If you already have your AVE ticket, you can get the suburban train ticket for free in the automatic vending machines, by typing the code for “cercanías” that appears in your AVE ticket.
