Hello, I would like to assist you today.
I have never been to Spain myself, but I have learned a lot about travel in Spain from my grandmother who was an avid traveler, and I myself traveled to Kuwait with my uncle when I was about 12, so maybe not as a young child, but I do know how it feels to be a child in a strange new country. In any new place, it is best to keep your eye and attention completely on your child; stay aware of your surroundings as well, but keep engaged with your son letting him as well as others around you know that you are fully protective of him. Also, don't try to force your son to participate in any activities that he may feel uncomfortable with or just doesn't want to. At the age of 3, this might not be a problem, he may want to do it all, but just in case, remain flexible so that he enjoys himself, and as a result, you do too. From everything that I have heard, Spaniards are family oriented people and love children. You definitely want to be weary of strangers, but I have heard that it's not uncommon for adults to speak to children and be courteous and engaging. Here is a very comprehensive Wiki article that gives some tips on traveling in Spain: http://wikitravel.org/en/Spain
Here as well is a children's guide to activities that may be good for your child in Andalucia: http://www.andaluciatravelguide.com/andalucia-for-kids.html
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