Recommendations from Switzerland to Lisbon

Would you like to do a roundtrip with those 10 days ?

I’ll suggest 2 routes and then you can choose. You may stop along the way of course!

Option 1 : fully reservation-free until Barcelona

• Geneva - Lyon or Valence - Avignon - Cerbère - Barcelona

TER trains in France are rather infrequent so pay attention to the timetables. Even worse in Spain!

Other options too like Toulouse and the Pyrénées (Latour) instead of the coastal route to get to Barcelona.

You’ll require reservations after Barcelona. Feel free to get them at a Spanish counter if you want flexibility :

• AVE Barcelona-Sants - Madrid-Atocha 10€ → frequent service, availability the day before
• followed by https://www.seat61.com/trains-and-routes/madrid-to-lisbon-by-train.htm (could sell out a few days in advance)

Option 2 :

• Geneva - Lyon/Valence - Avignon - Narbonne - Toulouse - Intercités to Bayonne (1.60€ reservation, AFAIK it cannot sell out) - Hendaye
• Euskotren Hendaye - San Sebastian 3-4€ ticket, get ticket at the station (Interrail not valid)
• to Vigo either via Vitoria/Gasteiz and the countryside (2 reservations required) or the very slow but very scenic route along the coast via Bilbao, Santander and Oviedo. Ticket required until Bilbao (Euskotren) and then pass valid.
• cross-border train Vigo - Porto
• Porto - Lisbon

General advice : https://www.seat61.com/interrail-and-eurail-reservations.htm

Another helpful link (although based from London, the last part will be useful to you) : https://www.seat61.com/Portugal.htm

Unfortunately the so convenient Hendaye - Lisbon has been cancelled and is unlikely to return in the near future. No night trains at all in Spain and Portugal!