Not only is Madrid a good starting point for your trip around Spain, it is also the perfect 'rest point' on a journey between Andalusia and Barcelona - the two most popular destinations in Spain. Barcelona is 12 hours by train from Granada, so a stop off in Madrid is ideal.
Read more about Suggested Itineraries from Madrid
Assuming you have both Andalusia and Barcelona on your Spain itinerary, there are three sensible ways of using Madrid on your journey:
- Starting in Madrid and passing through it a second time on your journey A short stay in Madrid would be recommended if you are taking this option. Then move on to Andalusia (or Barcelona), before returning to Madrid for a couple of days, perhaps doing a day trip to Segovia or Toledo, before going on to Barcelona (or Andalusia). If possible, I would recommend flying out of Barcelona, so that you don't have to return to Madrid for a third time.
- Starting in Madrid, taking a detour via Valencia, before ending in Madrid Much like the above option, heading south from Madrid to Andalusia but instead of passing through Madrid on your way to Barcelona, go east to Valencia before traveling up to Barcelona. You can then finish your journey again in Madrid. This is probably the easiest route as it allows you to depart from the same city you arrived in.
- Starting your journey in Barcelona or Andalusia followed by an extended stay in Madrid Using Madrid as a rest point between Andalusia and Barcelona. You only visit Madrid once, which may be preferable, but international travel out of Andalusia can be tricky (with the UK and Germany likely to be your only options) so you may have to return to Madrid or Barcelona anyway. Read more on Starting Your Journey in Barcelona.

