We are planning our first trip to Spain in September for 18 days. We would like to visit Madrid, Barcelona, Seville, Granada, Malaga and Nerja.We will use the public transportation. We can start from Madrid or Barcelona. We need your suggestion how to map out our itinerary.
Thank you.

If you want to get a good itinerary, check maitaitom's trip report:

Trip Report MaiTaiTom's "Insane For Spain" - 2015 - Fodor's Travel Talk Forums

If it doesn't come up, do a search for 'Spain' and you should get it and scads of ideas. maitaitom and friends drive rather than using public transportation but you should get good places to see.

Loads of threads on this - trains are the way to go

Madrid, Barcelona, Seville, Granada, Malaga and Nerja.We will use the public transportation. We can start from Madrid or Barcelona.

18 days

how about:

Barcelona - 4 nights
Madrid - train - 4 nights
Seville- train - 3 nights
Granada train or bus - 2 nights
Nerja bus - 2 nights
Malaga bus - 3 nights
Fly out last day.


(not sure about nerja - no train service apparently so check buses and how best to get back to Madrid but ideally fly out of Malaga or end point.

For lots on trains check www.budgeteuropetravel.com; www.ricksteves.com and www.seat61.com - latter superb on helping you book your own train tickets in advance at a discounted fare if early enough. You could also with that many longer train trips investigate the Spain Railpass (at sites I give above)- still have to make required reservations before boarding at about $10-15 a train above pass cost however.