My daughter attends crecer in Tamarindo Costa Rica in the summer for 4-6 weeks this year 12 weeks, only up to age 6.

Honestly Miami suffices, in our experience!

I would stick with South America, somewhere like Peru or Argentina. Most Spanish speakers in the US are Latin American. There are small differences in their Spanish and worth hearing the differences.

Realizing this is too late for Summer 2024, we sent our 11 and 13 year olds to Spanish language and watersports camp at Calanova in Mallorca for a week this summer. The Spanish teacher was kind and creative (although the class was a bit too beginner for them) and they had a fantastic time with the water sports. English seemed to be the default language for the very international student body, so if the top priority is Spanish practice, it's probably not the best fit. But if you want your kids to have a great time and learn/speak a little Spanish, I highly recommend it!
https://www.portcalanova.com/en/camps/day-camp.

Anyone have any recs for Mallorca?