This 500-metre tunnel connects both sides of the peak at Sierra Carbonera.
This 500-metre tunnel connects both sides of the peak at Sierra Carbonera. / A. Bolton

A 'mini Normandy' on Gibraltar's doorstep

  • A new tour run by the San Roque tourism office takes visitors inside German bunkers and a military tunnel overlooking the Rock

While Gibraltar is well known for its World War II heritage, it's a little known fact that La Línea also boasts its fair share of bunkers, military tunnels and pillboxes.

Although there are several well-preserved bunkers just a short walk from the border between Spain and Gibraltar in Princess Sofia Park and along the beaches of the isthmus, the largest concentration can actually be found nestled atop the Sierra Carbonera, behind La Línea.

In fact more than 100 German World War II bunkers, countless pillboxes and a 500 metre-long military tunnel connecting both sides of the peak can be found on ‘Charcoal Mountain’.

And unlike the structures in La Línea town centre which are sealed to keep the public out, the bunkers and tunnels on Sierra Carbonera have been left as they were, complete with 1940s graffiti that is still readable on the walls.

To highlight these fascinating historical remnants of the 1940s, the tourism department of San Roque has launched three new guided tours of the area.

Carlos Jordan, San Roque tourism coordinator, who helped design the tours, takes visitors inside several of the better preserved bunkers, before walking them through the military tunnel that connects the eastern and western sides of the Sierra Carbonera mountain.

He told SUR in English: “We are privileged to have a lot of singular historical sites and noticed a growing interest in the Second World War all over the world and particularly in Europe. People may not know that the Campo de Gibraltar area has the highest concentration of World War II fortifications and installations in Spain [over 500 bunkers]; the other main area fortified was the Pyrenees. 

“Over the last few years local historians Alfonso Escuadra, Ángel Sáez and César Sánchez de Alcazar had written books about the bunkers in the Gibraltar area and the Strait. We thought it was time to set up sightseeing tours as a lot of local bunker enthusiasts go out into countryside on walks and taking pictures of the bunkers and there are several Facebook pages in the area about these military installations.”  

Carlos added that the most interesting part of the tour is crossing the 500-metre tunnel connecting the San Roque side of Sierra Carbonera and the La Línea side, as well as the views of Gibraltar, the Bay of Gibraltar, Ceuta and Morocco.

He explained: “If you use your imagination a bit, it can take you back to 1940-1945 and [you can] imagine what it would like to be one of thousands of Republican prisoners of war working around the clock to prepare Spain for a potential Allied attack or Spanish involvement in the war if the Germans had succeeded in capturing the Suez Canal.” 


The origin of the bunkers stems from when France fell in 1940, leaving Gibraltar as the only place on Continental Europe opposing the Axis Forces.

Franco, who was sympathetic to the Axis powers of Germany and Italy, feared that Britain and France might try to invade Spanish soil via Gibraltar or Morocco.

The view of La Línea de la Concepción and Gibraltar from the bunker.

The view of La Línea de la Concepción and Gibraltar from the bunker. / A. Bolton

This led to the German and Spanish intelligence services joining forces to spy on the military and naval facilities in Gibraltar, which they saw as important strategic targets for sabotage.

The Spanish dictator, with the help of the Germans, built roughly 650 bunkers between 1940 and 1944 between Conil de la Frontera and San Enrique de Guadiaro.

This was done using up to 15,000 Republican prisoners of war, and although the highest concentration are on or under the Sierra Carbonera mountain, many more bunkers can be seen in towns like Tarifa and Algeciras or resorts such as Alcaidesa, Sotogrande or San Roque Club.

This is why the Strait of Gibraltar is the only place in Spain to feature World War II period bunkers, apart from the Pyrenees and the Canary Islands.