Cádiz is one of the Spanish provinces with the most beaches, many of them with a blue flag and which are chosen by thousands of people every summer to spend their vacation days. In this case I will focus on the beaches of San Roque so that you can decide which one interests you the most or which is better according to the characteristics you are looking for in them:
– Torreguadiaro or de las Conchas beach : It measures 1,300 meters and has a very high occupancy, as well as a beautiful promenade. It is of dark sand and stones, its waters are calm and among the many services it has you can find hammocks, umbrellas, showers, parking, bus stop and several restaurants.
– La Alcaidesa or El Balneario Beach : It is in the La Alcaidesa Urbanization and measures 840 meters. It is almost virgin, rustic and nudist, with a medium occupation. Its sand is dark and there is moderate swell, with very clean water. Among the services available you can find parking, showers and shaded areas.
– Sotogrande Beach : It goes from the exclusive Sotogrande Urbanization to Torre Carbonera and measures 5,450 meters. It is of dark sand and moderate waves. You can go on foot from the urbanization and it is also very close to the Sotogrande Sports Port. 
– Guadarranque Beach : It has fine golden sand, with very calm waters and measures 800 meters. It has parking, a bus stop, showers and a nearby Roman site that is worth visiting. It is 4 kilometers from San Roque.
– El Cabrero or Cala Sardina beach : It measures 900 meters. and it is a virgin beach with dunes and a low occupancy although on weekends there are many more people. Its sand is dark, the water is very calm and you have restaurants, showers, toilets and many more services.