The archaeological collection is formed by the old collection of the Municipal Museum of Balaguer with the archaeological materials from the excavations made between 1969 and 1973 in the Formós Castle and other materials from several interventions carried out in Balaguer and La Noguera after the Decree 155/81 of June 11, which approved the regulation of archaeological excavations in Catalonia. 

It is remarkable the collection of Andalusian materials from the archaeological site of El Pla d’Almatà or the various urban interventions carried out in the madina of Balaguer, which constitute one of the most important and exceptional medieval groups of the 10th and 11th centuries. To these must be added, also from the same period, the materials from the Formós Castle, an old Andalusian palace which, after the conquest of the city of Balaguer, become the residence of the Counts of Urgell.

Among the prehistoric materials we want to emphasize the importance of the sites in Roca dels Bous, Llorenç de Montgai, in Cova Gran de Santa Linya and in Cova de l’Estret de Tragó; the protohistoric materials of La Pedrera de Vallfogona de Balaguer and La Colomina de Gerb; and the Hispano-Visigothic materials from El Bovalar de Serós and from the necropolis in Palous de Camarasa.