The Museum of Badalona was built upon the Baetulo Roman Thermae, which were discovered by archaeologist and historian from Badalona Josep Maria Cuyàs i Tolosa in the year 1955, when the area known as Clos de la Torre was undergoing urban development. The construction of the Museum’s current location commenced on August 12 of the same year and by the end of 1957 both the underground and ground floor areas had been built. From then on the Museum opened its doors to the public although the actual totality of the building would not be finished and officially inaugurated until January 30, 1966.

During the first years, the Museum was also the Town’s House of Culture, gathering a number of cultural entities and hosting a wide range of cultural events. In the late seventies end early eighties the Museum oriented its activities towards the restoration and recovery of the historical heritage of the town. As a result, the Town’s Historical Archive was created in 1979 and located within the Museum’s building. At the same time, the Museum managed to restitute the Venus of Badalona, the Tabula hospitalis, the hinges of the town walls’ door and Can Peixau’s Iberian Stele, all of which originally belonged to the early Museum founded by the Hiking Society of Badalona in the thirties, but which were stolen at the end of the Civil War.

In more recent times, the Museum has gradually incorporated new sites from Roman times into its structure, which has made it possible to document what everyday life was like in the town of Baetulo. Among these sites we can find the Garden of Quintus Licinius, the House of the Dolphins, the Conduit of Waters or the monumental complex around the Decumanus, located near the Forum, on the same site as the Thermae.