http://www.mazarron.com/Leisure/Senda/guns.htm
Attached is a link to the web page for the guns, we had an enjoyable few hours up there expoloring the old place. A little tip for you, take a torch with you so you can explore the many underground walkways, we did in pitch black conditions using the flash of the camera.
After visiting if you fancy some lunch we can recommend going to what was known as the Australian bar in La Azohia, now called Antipodus, this was right at the far end of the village after passing the jetty and serves a lovely menu del dia overlooking the bay with Mazzaron in the distance.