Flying into Madrid and out of Barcelona. How should I spend 10 days?
It sort of depends on what kinds of things you like to do/see on vacation. Art museums? Historical sites? Nightlife?
Both Barcelona and Madrid warrant 2 days minimum, more if you are interested in day trips (like Montserrat, Toledo, Segovia, etc.). Places that are probably most frequented by first time visitors include the aforementioned Barcelona and Madrid, as well as Granada, Seville, Cordoba, and the White Hill towns in Andalucia. You won't have time for all of them, but if you gave us some indications of the types of things you are looking for, we may be able to help narrow it down.
The rough itinerary I had in mind was 3 nights Madrid and 1 night in Toledo at beginning of trip and 3 nights in Barcelona at end of trip. I have a pretty good idea about what I want do in those cities. Trying to decide how to spend the middle 3 days/nights. My thought was Seville & Granada, probably not enough time for Cordoba or WH Towns. Any suggestions for sites, day & night, in these two cities for two 20-somethings?
Cordoba you can do as a stop on the AVE from Madrid to Sevilla. Leave Madrid early AM, spend several houres in Cordoba, then catch an evening train into Sevilla.
Be aware there are no fast train links Madrid-Granada, so you may want to consider catching the overnight train to Barcelona directly, or discount airline Vueling, also Granada-Barcelona direct.
Toledo is a definite Must! Take the train from Atocha in Madrid and be in Toledo in less than 1/2 hour..frequent departures during the day. If you get there early, one night would be sufficient, allowing you two full days with a late departure back to Madrid the next day. Great hostal there is Posado de Manalo, near the Cathederal, central location, and if you get lost you can easily find the Cathederal. Lots of walking for sure.
Madrid - great waling city...The Prado and Park Retiro would be definitely on my list.
Have a great trip.