The Museo Naval Cartagena sits right on the city's waterfront, housed in a fascinating 18th-century building that has lived many lives. When I first walked through its doors, I was struck by how the architecture itself tells a story – this place has been everything from a prison to a sailors' training barracks before becoming the naval museum it is today.

What makes this museum particularly engaging is its connection to Isaac Peral, the Cartagena-born naval officer who designed one of the world's first electric submarines. The original Peral submarine is displayed in a separate hall that was once the arsenal's foundry, and seeing this pioneering vessel up close gives you a real sense of the innovation that emerged from this Mediterranean port city.

The collections spread across multiple themed rooms, each focusing on different aspects of naval history. I spent considerable time in the cartography section, where copies of medieval maps and Columbus's 1492 letter remind you of Spain's maritime legacy. The diving equipment room showcases the evolution of underwater exploration gear, from heavy brass helmets to more modern apparatus.

The Arsenal room particularly caught my attention with its display of 18th and 19th-century shipbuilding tools. These weren't just decorative pieces – you can imagine craftsmen using these very hammers and saws to build the warships that sailed from Cartagena's historic port. Remnants from the famous treasure ships Nuestra Señora de Atocha and Santa Margarita add another layer of maritime adventure to the story.

One unexpected highlight was learning about the 1873 bombardment of Cartagena through actual cannonballs and historical documents displayed throughout the museum. This local history gives context to the broader Spanish naval narrative.

The museum operates with somewhat limited hours – mornings only, and closed Sundays and Mondays outside summer months. An audio guide is available if you want deeper explanations of the technical aspects, though the displays are reasonably well-labeled. The entrance is technically free, though they appreciate voluntary donations.

Located in the Region of Murcia, the museum benefits from its maritime setting. You can easily combine a visit here with exploring Cartagena's Roman theater or wandering the port area. The building itself, designed by military engineer Mateo Vodopich, represents the kind of practical 18th-century architecture that has endured remarkably well along Spain's Mediterranean coast.