The Tetuan Square Air-Raid Shelter is a unique military-historical site hidden deep underground in the center of Castelló de la Plana. Today, this space has been transformed into a modern museum, part of the MUCC (Museu Urbà de la Ciutat de Castelló) network. It was opened to the general public in 2018 after an extensive scientific restoration, becoming an important symbol of historical memory preservation in Spain.

The shelter consists of an extensive network of tunnels located at a depth of about 12 meters. The space was designed to accommodate up to 200 people at a time. Visitors can see the original entrances, narrow staircases, and characteristic zigzag passages, which in the past served to dampen blast waves.
Inside the museum, a special immersive atmosphere has been created: the underground halls are equipped with information panels, maps, and audiovisual installations. This site not only tells the story of the technical side of building protective structures but also encourages reflection on the value of peace and tranquility in modern society.