Planning the Spain part was easy because I don’t know when I’ll arrive but I know when my flight leaves Barcelona. Four nights in Barca now seems like enough, but who knows.
If I’m running out of time before Barca, then entering Spain via a ferry from Tangier to Algeciras is the obvious choice because it’s on a rail line. If there is time to see some of the Andalucia region, then Tarifa because it’s small, low key and a 90 minute bus ride from the first step on the Cadiz – Seville – Cordoba rail route.
Andalucia has too many treasures. The Alhambra is extraordinary but Granada is not close to anything else on my list. At the very least I expect to stay in Cordoba for 4 reasons. High speed rail to Barcelona starts there. Day trips, time permitting, to Seville are a 45 min train ride. It will be week 4 of the trip. On long trips, a slow and easy 4th week works wonders for me. Cordoba has <200k population. It sounds slow and easy.
Although I expect to return to Spain because this trip is only a taste, I won't know what time of year that will be. It seems I should grab a brass ring I learned about a few days ago: Feria de Jerez, also known as Feria del Caballo (Horse Fair) in Jerez. http://en.wikipedia.org/wiki/Feria_de_Jerez