This is a group of Spanish Civil War defence trenches. Although they were never used, their main objective was to organise the defence of the peripheral territory of the Spanish Navy Base in Cartagena in two territorial fronts: one in the land, as defence of a possible attack coming from inland; and the other maritime; in order to strengthen the non battery covered coastal areas in case a possible troop landing. In Guardamar district, the advanced resistance line began in the coastal dunes, between Guardamar and the beach. This defence line was followed, further inland, by several trenches dug (second line of fire) on the Montcaio Hill and the Raboses Hills and several others to the west till the Raiguero and Cabezo Lucero trenches.