We are spending 3 days in Seville in August and would like to spend 3 days at a beach! What would you recommend?
I would head to Cadiz
You might find these links of interest:
https://www.theguardian.com/travel/2015/jun/26/huelva-andalucia-holiday-guide-spain-cadiz
Across the bay from Cadiz in the small town of Rota. It has a nice beach. It is very busy in August as it seems to be a favorite destination for Germans. Two nice hotels are Playa de la Luz just outside of the main town, and the Duque de Najera downtown. There is a ferry that goes between Rota and Cadiz. Near Rota is Chipiona. It too has a beach, but there isn’t much else to do there. There may be a nice beach near Huelva, but I haven’t been to that town in 35 years.