Can you recommend a summer school or camps in Spain for Kids?

My family is planning a trip to Spain and we want to send the children, elementary school age, to summer school or camp to develop their Spanish. We are ideally looking for a high level public or private elementary school with summer classes in Spanish with local kids. Our children are already fairly proficient in Spanish, and we want them to have the opportunity to learn more while playing with local kids their age. Looking for the months of July and August 2015. Does anyone know of any such school or camp? We are flexible about location in Spain. Any advice or suggestions would be appreciated. Thank you.