Red Eléctrica, the Redeia’s company responsible for electricity transmission and the operation of the national electricity system, has undertaken the cleaning and restoration of three defensive casemates in Bristol, Corralejo, which are part of the set of fortifications built along the north of Fuerteventura during the Second World War.

The project comprises the cleaning of the casemates followed by their restoration by consolidating the structural elements of the fortifications, thus avoiding their degradation, and is carried out in the framework of the Environmental Impact Statement (EIS) of the  Puerto del Rosario-La Oliva 132 kV double-circuit line.

During the Second World War, a series of fortifications and trenches were built in the Canary Islands archipelago as a defence against a potential occupation by the Allied side.

There are 47 machine gun emplacements and 8 casemates to be found on the east coast of the island of Fuerteventura. Of these, five are located in the north of the island, intended for anti-aircraft defence in Corralejo. Another three are situated in the south, to cover the Jandía area with coastal batteries on the Cuesta de la Pared. All these data are provided by the research study "Catalogue of military fortifications of the Second World War in Fuerteventura" carried out by the researchers Javier Sánchez Sosa and Yubal Curbelo Cabrera.

The casemates being restored by Red Eléctrica consist of a circular moat and a concrete platform, where a fixed artillery piece was installed. Access from the outside is via a ramp tunnel. From the moat, and through the tunnel, visitors can also enter two rooms used for storing ammunition and gunpowder, or as an air-raid shelter in the event of bombardment.

The casemates are part of a set of infrastructures which includes an area for a searchlight, an excavated and concreted firing position, and a bunker for the command and observation post, which was used to advise the artillery of the casemates.