We stopped at a series of lakes south west of Ossa de Montiel, 20k west of Albercete on the N430. We had been driving since lunch time and passing very little but olive groves and wheat fields until we turned down a narrow lane and the lakes came into view. As we turned the corner we saw the place was heaving with people. There were restaurants and bars, people were swimming in the lake, having picnics, music was blaring. The campsite itself was very busy, mainly families with young children. We realised it was Friday, 1st May and a national holiday.