Know Before You Go
The guns are an amazing sight and you have to ask yourself how the authorities simply allow the public to wander about and even climb all over them. It is likely that the authorities will start to charge for entry and closely control access in future.
To get to the Bateria from Mazarrón, take the RM-332 road which goes over the hills Cartagena, turning off at the roundabout with a lighthouse on it onto the E-22, towards El Mojón and then through Isla Plana. About a kilometre further on, turn right onto the RM-E23 to go through Campillo de Adentro and carry on past the large wooden notice board with a hikers route map just after crossing the Rambla de Azohia. Then follow a narrow and winding, former military, road to the crest of the peninsular. It is not a drive for drivers of a nervous disposition. After awhile you are likely to worry if you are on the right road as you climb higher and higher up to about 850 feet altitude before descending a little before you reach the parking and turning area. You may be unlucky enough to meet vehicles coming in the opposite direction. There are occasional passing places so take it steady and try to anticipate. The views along this road are magnificent but for the drive sightseeing is best left until the car is parked.
There are no toilets and no catering at the site so be prepared.