Chile Sandboarding: Iquique or San Pedro de Atacama?

Hello, I have read that sandboarding is possible in both Iquique and in San Pedro de Atacama. I'd like to do it but probably just once. Does anyone have recommendations as to which would be a better place to do this (I'll visit both places anyway). I would be a beginner, having snowboarded just once in my life about 10 years ago. Thanks,
Alex