We are planning on taking an overnight train from Valencia to Granada. I am unable to book the tickets via the internet or the renfe phone system, the operator said it was because it was an overnight train. Do you think it will be a huge problem to buy the ticket when we get into Barcelona? (we're flying into Barcelona and then going to Valencia).
Thanks, I've searched for threads on this topic, but haven't found an answer.
superk

I made reservations on an overnight train from San Sebastian to Madrid with http://www.raileurope.com/us/. I didn't want to take the chance, I wanted a comfortable place to sleep.