The air raid shelters beneath Almería are among the most extensive surviving examples of Second World War civilian infrastructure in Spain, and the guided tours through them are genuinely moving. The tunnel system — nearly 4.5 kilometres of passages dug by hand in 1937 — runs beneath the old town and could shelter the entire population of the city during bombing raids. The shelters include dormitories, a surgery, a pharmacy, a water cistern, and ventilation shafts that still work.
Tours run from the visitor centre near the Alcazaba and take about an hour. The guide explains both the engineering achievement of the tunnels and the human context: Almería was a Republican city surrounded by Nationalist territory, subject to artillery fire from land and sea. The story of the civilians who sheltered here — and the bombardment of Almería by a German warship in May 1937, which provoked international outrage but no effective response — is told with appropriate seriousness. Bring a jacket; the temperature underground is considerably cooler than on the surface.