Walking through the Refugio Museo de la Guerra Civil in Cartagena feels like stepping into a chapter of history that most people only read about in books. These aren't just old tunnels under the city - they're authentic air raid shelters carved into the rock during Spain's Civil War, when Cartagena became one of the most heavily bombed cities in the conflict.

The story behind these galleries is quite remarkable. Construction began in 1937 as German and Italian planes pounded the city relentlessly. Cartagena was a strategic Republican stronghold, serving as the main port for Soviet aid and housing important weapons factories. The famous "four-hour bombardment" of November 25, 1936, had already shown residents just how vulnerable they were.

What strikes you immediately is the scale of the operation. These particular shelters on Calle Gisbert could accommodate around 5,500 people, making them among the largest in the city. Twenty different entrances allowed quick access from the streets above. Walking through the tunnels today, you can still see sections that were never finished - the war ended before workers could complete their task.

The museum does something clever with the space. Rather than just showing you empty corridors, it uses the galleries to tell the broader story of how ordinary people survived during wartime. One section explains the different types of shelters built around the city, while another focuses on daily life under constant threat of bombing. You learn about the Passive Defense Committee, which organized shelter construction and distributed safety instructions to residents.

The audiovisual presentation uses original footage from the period, and hearing actual air raid sirens echoing through these stone corridors creates an unsettling but powerful experience. The audio guide, available in several languages including English, adds helpful context as you move through the different sections.

What I found most compelling was how the museum balances historical education with respect for the people who lived through this terror. The testimonies from survivors remind you that behind all the military strategy and political context, real families spent countless hours huddled in these underground spaces, never knowing if their homes would still be standing when they emerged.

The modern entrance building provides a stark contrast to the rough-hewn tunnels below, designed by architects who understood they were creating a bridge between past and present. It's a thoughtful approach to preserving a piece of history that might otherwise have remained forgotten beneath the streets.