The San Anton Necropolis surfaced during construction in 1967, and the museum's director, Pedro San Martin, saw at once what it demanded. Instead of relocating the find, he proposed to the city council that a new museum be raised around the site itself, preserving the graves in place. It was an ambitious idea, and an expensive one. The council acquired the land and paid to adapt the building, but the work dragged, and the museum did not open its new home until 1982, years behind schedule. The wait bought something no ordinary display case can offer: the necropolis remains the beating heart of the institution, visible from point after point along the galleries, the artifacts of the living arranged in orbit around the resting place of the dead.

The collection is far older than the building. Cartagena has guarded a set of Roman inscriptions since the late 16th century, and in the 1800s the Royal Economic Society of Friends of the Country began gathering antiquities in earnest, much of it drawn from the mineral-rich mining district of Cartagena and La Union. That effort produced a Mineralogical and Antiquities Museum in 1883, the seed from which the modern institution grew. The Municipal Archaeological Museum itself was formally founded on the 25th of October 1943 under its first director, the archaeologist Antonio Beltran Martinez, opening in humble quarters before its collections outgrew one home after another.

Beneath Cartagena lies Carthago Nova, the New Carthage that Rome seized in the Second Punic War, and the museum's holdings reflect that depth. The exhibits run from the Middle Paleolithic all the way to modern times, but it is the Roman city that dominates, as it dominates the ground underfoot. The galleries are organized to teach: artifacts arranged chronologically on one floor, then grouped by site and excavation on the next, with the necropolis visible throughout. Among the treasures are a celebrated collection of Latin epigraphy, the carved inscriptions through which the Romans recorded their lives and deaths, an Iberian wine-jug, and a delicate Hellenistic earring from the second century BC, recovered from the city's Roman amphitheater. Because excavation never stops in the historic center, the collection keeps growing, fed by discoveries made whenever the modern city digs into its ancient foundations. Every new building project is also, potentially, a new dig.

This is not a mausoleum of dusty cases but a working research center, and part of the wider Regional Network of Museums of Murcia. The museum houses libraries, workshops, and photographic and restoration laboratories where new finds are cleaned, studied, and stabilized before they ever reach a display. Its collection traces its own long lineage back to the Mineralogical and Antiquities Museum of 1883 and, further still, to the Roman inscriptions the city has guarded since the 1500s. Once a year, during the Night of Museums, the doors open free to all, and the people of Cartagena come to stand above the necropolis their forebears chose to preserve. Few museums so plainly embody their own mission. Here the act of remembering and the thing remembered occupy the same walls, the past kept exactly where it was found.