Bunkers del Carmel

The Bunkers del Carmel occupy the summit of Turó de la Rovira, a hill in the Gràcia/Horta district that was fortified during the Spanish Civil War with anti-aircraft gun batteries designed to defend Barcelona against Nationalist and Italian bombing raids in 1937–38 — some of the earliest coordinated urban anti-aircraft defences deployed anywhere in that era, since Barcelona was among the first cities in history subjected to sustained aerial bombardment of civilians.

After the war, the site's abandoned military structures were informally settled by families displaced by the conflict and later by migrants arriving in Barcelona during the mid-20th century, forming an improvised shantytown that persisted on the hilltop for decades until it was finally cleared and the site converted into an archaeological park in the 2000s, preserving the concrete gun emplacements as historical monuments rather than demolishing them.