Barcelona to Lisbon via Southern route

Hi!

The coast between Murcia and Granada/Malaga has poor public transportation.
"Poor" does not mean "impossible": Valencia to Cartagena is a 4-hour train ride, and Cartagena to Granada is a 6-hour bus ride (ALSA).
And Seville to Lisbon is best done by plane.

What is tricky, in my opinion, is visiting natural areas without a car. In any case, I tried to allocate 21 nights to your listed sights (I suggest Granada instead of Málaga) and I do not have any time left for such areas.

Here is what I come up with:

• Barcelona 4n
• Tarragona 2n
• Valencia 2-3n
• Cartagena 2n
• Granada 2-3n
• Sevilla 4n (incl. day trip to Cordoba if possible)
• Lisbon 4n

By the way, Nazaré is not worth the day trip in my opinion. If you want to see the coast, the area between Cascais and Ericeira is much closer and arguably better.

I do have another plan suggestion for you, though. Cartagena has good Roman ruins but is really a long way from anywhere, and Valencia, while lovely, is perhaps not the most obvious choice for a first-time trip to Spain.
I would personally replace Cartagena with Mérida, and do the following:

• Barcelona 5n including day trip to Tarragona
• Cordoba 2n
• Granada 2n
• Ronda 1-2n - this would enable you to go to a more mountainous area with workable public transportation
• Sevilla 3-4n
• Mérida 3n - best Roman ruins in the Iberian peninsula, and possible day trip to Cáceres
• Lisbon 4n (by bus from Mérida)

Forget Nazare, a tourist filled beach town.
Consider Alcobaça, Obidos, Evora.

Because of the radial nature of Spain’s rail network, you will find logistics difficult if you route through Cartagena. I’d suggest heading straight on to Cordoba (via Madrid) for a stand alone stay of 2 nights.

Barcelona 4n
Tarragona 2n
Valencia 2n
Cordoba 2n
Granada 3n
Sevilla 3/4n
Lisbon 4/5n