Human remains that can offer a lot of data about our past, sediments with a lot of information about what was eaten centuries ago, textile machines, computers, amphorae, tombstones, sculptures, paintings, murals, capitals, clothes, fossils, stones, seeds, bullets, pitchers... If we were to add up the heritage guarded by Catalan museums, the figure would reach eight million pieces. It is an unreachable and heterogeneous collection of which the public only sees a very small part in the exhibition halls; the rest, the vast majority, remains invisible in warehouses and depots.