Get a dose of vitamin D at Playa El Arenal/Playa Pedrucho. After you've topped up your tan, hang around and watch the sky change color as the sun sets.
You'll have no end of sightseeing choices when staying in San Javier. Playa El Arenal/Playa Pedrucho is a good place to start here, but there are many other worthy attractions to check out. Mar Menor, Puerto Deportivo Tomas Maestre, and Alcazaba Zoco are close to the stretch of coastline and will top off your day nicely.