Before heading home, we have 3 open days when tour ends in Sevilla. Suggestions on where to go/stay during those days? We love coastal towns.
Málaga, Cádiz, are in the vicinity. Or San Sebastián (it is far from Seville though).
At the end of the RS Spain Tour in early May 2016, I spent one extra night in Seville, two nights in Córdoba, and three nights in Jerez de la Frontera, which was during their annual Féria del Caballo, and during which I also made a day trip by train from Jerez to Cadiz. Of these, only Cadiz is on the coast, but it was also the least interesting and enjoyable of the three, at least for me. I highly recommend Córdoba, the Mesquita is amazing, there are other interesting sites, and just exploring the town was very enjoyable, day and evening. I can recommend a fine apartment near the Mesquita if you are interested.