Great time to travel, wonderful memories to be made.
Some thoughts"..........
Tap water is fine and you need to stay well hydrated.
Train travel is excellent, be sure and take an AVE train. Second class tickets equal business class airline service. Fantastic experience for anyone, especially the kids. Btw the train stations are a great place to explore.
If you have not purchased airfare then strongly recommend you fly directly, via madrid, to seville. This makes for less stressfull, more efficient travel.
Instead of staying in hotels highly recommend renting an apt for aplaces where you stay a minimum of three nights. Advantages are more space, separate bedrooms, kitchen and we believe better economic value. Plus we find the landlords are more engaging and desire for you to have a successful experience in order to privide a great recommendation. To test the waters try airbnb website.
Consider three nights in seville, five nights in madrid and four nights in barcelona. This will provide a well paced opportunity to experience three disticntly different areas of spain. Seville is old culture and the place for taking in a flemenco show. You can stop in Cordoba on your way to madrid as part of a day trip.
Madrid offers an excellent subway system. Retireo parc is a great experience for a family picnic, compareable to central park in nyc. Ez to do toledo as a day trip.
Barcelona offers the beach! End the trip on the beach of the Med in true relaxation mode.
Then fly out of barcelona.
Anyway you do it, have fun!
Oh! Pack lite. Really lite. Lugging luggage is a real trip killer.
