On July 1936 Spanish Civil War broke out. Pro-Franco navy and airforces, with the help of Italian and German allies, bombed civilian and military republican targets. This new model of war led to the construction of several systems of air defense and sea defense throughout the Mediterranean coast.

The coast of the town of L'Ametlla de Mar, situated between Tarragona and the Ebro delta, was fortified by the Generalitat of Catalonia and the Spanish Republic. At that time suspected of a possible landing of the national army from Mallorca.

Although never produced this landing, the fortification process did not stop as possible. So, they built fortifications that covered the entire coast of the municipality, from San Jordi d'Alfama, cala Mosques and cala Nova to the port de l'Estany and the punta de l'Àliga. For reasons of visibility and condition, the structures of San Jordi d'Alfama and the Port de l'Estany are the most prominent.

In the case of San Jordi d'Alfama highlights the spectacular machine gun nest located very close to the sea, with fortifications remains of two very distinct periods.

But is the port de l'Estany where, there is no doubt, preserves the most important fortification. Is an artillery bunker that consists of a battery of three guns, with corridors and interconnecting rooms, allowing to protect the material and artillery crews. The location of this military complex is given by its privileged location overlooking the entire Gulf of St. Jordi. The military complex consisted of 3 platforms to accommodate brass cannon shell type model 1891 15 cm. The battery only managed to have it two of these guns. Currently, you can see the metal supports to curb the impact of firing recoil of these guns, obsolete during the war.

These fortifications were the work of labor battalions or fortification, which were sometimes aided by residents of the municipality for services not strictly military, such as carrying water or material. Civilian workers in L'Ametlla de Mar were paid a salary of ten pesetas a day. To all this must be added the necessary military personnel to provide the other additional defenses, resulting in a large movement of people.

The coastal battery of L'Ametlla de Mar didn't meet its goal, as the landing did not occur. On January 13, 1939 when Franco's army occupied L'Ametlla de Mar dismantled these republican weapons, although since the end of 1937 the battery was already obsolete.

L'Ametlla de Mar started in 2008 the rehabilitation of an artillery bunker, that was completed one year later. The interior of the bunker has been acclimated with decorated, has voiced and installed panels and period photographs, donated by the municipality. The restoration also discloses the daily life of ordinary people and soldiers, what they ate, how they slept and and what kind of life they did. It should be mentioned, the projection of a short film seven-minute black and white, without dialogue that tells the story of boy and girl of the municipality who relate to the soldiers hiding in the bunker. The tour ends with an explanation of the ships that sank in the years of World War I off the coast of L'Ametlla de Mar.