December - 10 nights in South of Spain - looking for guidance

If you are interested primarily in Andalucia, I would save Barcelona for a future trip. Round trip to Madrid works fine, but you could check how the open-jaw flights to airports in Andalucia shake out.
If Madrid and Barcelona are your priorities, five days each would work well, or give the edge to whichever one interests you more. There are plenty of day trips to do from both.
Last, I would scope out how Christmas affects things.

Thank you. Can you recommend some good can't miss places that we could cover in both places. Trying to see how to spend the days effectively.

Neither Barcelona nor Madrid is in southern Spain, but airfares to those cities may turn out to be substantially cheaper than to Andalucia. Madrid is usually noticeably colder than Barcelona in December, but it's a more geographically-convenient gateway if you want to see the south. It's a rather long train ride from Barcelona to southern Spain.

For a December trip my focus would be Seville, Cordoba and Granada. Not only is weather lalmost guaranteed to be milder there (though Granada will probably be cooler than the other two cities due to altitude), but those great destinations are miserably hot during summer vacation season, so a winter trip there is ideal.

I'd add the extra day if possible; remember that days will be very short in late Decmber. If you feel you have extra time, Malaga or Cadiz, both on the coast, would be a possible additional stop.

All the places I've mentioned are connected by trains. Rail service to Granada is not very frequent, so many travelers end up using one of the comfortable Spanish buses to connect Granada and Seville.

Thank you for the details. That helped a lot.

Our itinerary is finally taking shape, how does it look?

Day 1: December 20 - Arrival in Madrid
Day 2: December 21 - Travel to Seville & Explore
Day 3: December 22 - Seville: Cathedral & Alcázar
Day 4: December 23 - Seville: Additional Day of Exploration
Day 5: December 24 - Day Trip to Córdoba & Christmas Eve
Day 6: December 25 - Travel to Granada & Christmas Day
Day 7: December 26 - The Alhambra & Sacromonte
Day 8: December 27 - Explore Granada & Albaicín
Day 9: December 28 - Return to Madrid
Day 10: December 29 - Madrid Exploration
Day 11: December 30 - Departure

I have not been to Spain yet, as I am planning a trip myself. My trip follows a different itinerary, but in my original plan I had contemplated a train to Sevilla on arrival day. If you can fly direct from your home, taking a train in the afternoon is similar to a connecting flight. Then you can avoid an extra check-in/check out and just do Madrid at the end of the trip. To me check-ins and check outs always consume time, so I try to avoid any unnecessary ones.

Yes, that is exactly what I wanted to do as well. My better half has made the point that we will have bags and finding the best option to connect from the airport to take the train could become a nightmare if not a hassle.

Yes, it can be cold in Spain, but usually not super freezing with heavy snow like parts of the USA East coast! However, it is not really warm enough to swim in any beaches.

Actually, I do like your new itinerary--it is much more slow paced and relaxed. I think you have allowed sufficient time to really see some of the sites in a meaningful way. My only thought would be that if you have the energy, you should go directly from Madrid airport to the train station and straight to Sevilla. Yes, you will have jet lag, but you can check in right away to your hotel and have more nights there instead of having to check in and out of a hotel in Madrid for one night.

A caveat would be to do a deep dive to check opening and closing hours of sites during the holiday season, as often there are religious celebrations which may have some impact on accessibility, especially for cathedrals. You may need to buy some tickets in advance online, such as the Alhambra.

I am also going to recommend that you consider making meal reservations for the holidays, just because some restaurants may be closed. Your hotels should be able to assist with recommendations.

Your children are at a good age where they can certainly learn in advance about some of the things they will see. You want to make the trip fun for them, not just a history lesson (but be sure to see Columbus' tomb!). They do need to learn why Andalucía is full of Moorish architecture.

If possible, consider going to a flamenco show, and maybe even a soccer game! Make sure you do a tapas dining time with them, and don't forget to try the chocolate and churros. Some people like to do fun things like bicycle tours with kids. The children should definitely learn and practice some Spanish!

There is so much to see and do in Madrid that I do not know where to start for just a day, but if you like royalty, consider touring the Royal Palace, if you like art, consider visiting the Prado, and make sure to get to the Plaza Mayor.

Here is Spain's official tourism website:
https://www.spain.info/en/

Have a fantastic time planning, and happy holidays. ¡Buen viaje!

Thank you for the detailed message. Yes I am going to convince my spouse about avoiding the check in/out in Madrid on day 1.

Appreciate the great points you made about involving the kids. Yes, that is what we want to do, encourage them to learn about cultures and places outside of their connected devices at home :)

Looking forward to some good food. Excellent idea about getting restaurant reservations. Have that in our to do list.

Great itinerary! For the kids, in Seville, recommend the rooftop tour of the Cathedral, churros and chocolate at Bar el Comercio, and hanging at las Setas.

Oh, and if you go directly to Seville and end up with an additional day in Madrid, highly recommend a daytrip to Segovia to see the aqueduct and the alcazar. Awesome for all ages!

Packing light would minimize the stress of airport to train station transportation. And the kids seem to be old enough to be totally responsible for their own bags.

For only 10 days each person should be able to pack light with one carryon and one small to medium sized personal item such as a pack pack the size of a book bag.

I’d try for open jaw flights into Madrid and out of Sevilla or vice versa. If you fly both into and out of Madrid I would not stay there the night you arrive but would immediately take a train to Granada. Spend two nights there then train to Cordoba and stay two nights. Next take a train to Sevilla and stay three nights. Finally take the train back to Madrid and stay three nights.

We did a cooking class in Seville and our then 15-year-old son loved it. It was in the Market and recommended in Rick’s book.

You can find my full trip report on our trip. We went to the same cities as you, but after Christmas.

My children were about the same age as yours when we took them to Spain. For the places you’re visiting that we visited, they enjoyed Madrid’s Royal Palace, the cathedral in Sevilla, and the Alhambra in Granada. They hated the Prado and couldn’t get out of it soon enough.

If you are serious about food, look at the site:

www.hungryonion.org

Example, one of my most recent trips to Cordoba; I travel solo and believe I spent five nights there.

https://www.hungryonion.org/t/cordoba-in-early-march-24/38548

I can offer more recent comments about Barbate, Vejer and around, Sevilla and Madrid. As I mentioned, i go solo and always book days ahed of my desired dates.

this winter will spend about a week in Barcelona before flying to Jerez (enchanting city with fantastic food and great hotels); I then rent a car at Jerez airport and continue on m journey to the area around Vejer and Medina and. Barbate.... One of my favorite restaurants in Spain is in Zahara de los Atunes.

Be prepared for cold weather in Granada and Madrid - it can go down to near freezing. You can ski an hour from Granada.

Thank you all for the valuable comments. Regular life/work got the better of me hence the delay in response.

We are focusing on Madrid and then Seville this vacation trip. In the process of booking tickets for train, sites to visit. Will definitely look up Zen Curated Travels, thanks for the tip. Exactly what we were looking for.

I realized the train schedules from Seville to Granada has not been released yet, so unable to book that. I will keep checking every day.