Barcelona to Athens by train is possibly the most difficult journey in Europe. You have to get to France, across Italy, through the alps to Budapest (or through Slovenia) and then find a route through the Balkans. It involves buses and night trains and then the Greek rail service, which is in chaos after a major accident a few weeks ago.

The other option is to make your way by train to the South East of Italy and take a ferry across to Greece. There are some which have a discount for pass holders.

 

First of all, thank you for such a detailed answer. I don't mind making stops at certain cities to get a glimpse of the city and avoid night trains. So there's no way the whole journey can be covered with a pass if buses are involved? I don't mind travelling more to avoid the buses. Moreover I am happy to do this trip in 4 days.

Could you please name the ferries with the discount? I am choosing train mainly because I have 2 big luggages and a hand luggage.

4 days is quite ambitious to do that all and you’ll barely have time to enjoy the 1000s of potential destination you’ll pass.

There are (overnight) ferries from Barcelona to Italy (Genova with GNV ferries or Civitavecchia (close to Rome) with Grimaldi ferries). The ferry Spain Italy takes at least a day about 20h.

Once in Italy where you could take the train to Bari, and then another ferry to Patras (Greece) and continue to Athens. But I doubt a pass will be good value for that trip.

Rein theoretisch kannst du von Barcelona aus mittags einen TGV nach Paris nehmen, morgens einen weiteren TGV nach Frankfurt und noch am gleichen Tag einen Intercity nach Wien. Von Wien aus mit einem Nachtzug nach Bukarest und von dort aus für 30-50€ mit dem Bus nach Athen. Von den Reservierungsgebühren für die TGV'S vielleicht nicht gerade günstig aber für die Länge der Strecke ok, dafür bräuchtest du 3 Reisetage+Müsstest was mit der Nacht in Paris machen ^^