The area of Planargia is embellished by the inestimable value of its archaeological and artistic heritage, as well as by the importance of the unique civilizations and cultures that settled here as the inevitable result of its geographical position and its natural resources. A long story told by its prehistoric “fairy houses”, locally knowed as domus de Janas, as well as by the amazing nuragic architecture, proof of the intense exploitation of the area in the protohistoric age. Then in the following centuries Planargia was conquered and ruled out by the Phoenician and the Romans, by the Pisan, the Aragonese, the Spanish, the Savoy and eventually, from 1961, by the Italians
The Phoenicians are credited as the having being the first to discover and exploit the advantages due to the geographical position of the region, given the presence of a navigable river and a country inland rich in natural resources. Their are indeed credited as the founding fathers of the town of Bosa and of its name. The latter being the historical capital of Planargia, documented and remembered even in Roman times, when the town was built on the left bank of the river, close to the site where nowadays it is stll possible to admire the beutiful architecture of the former Cathedral of Saint Peter Extra Muros, built according to Lombard-Romanesque style from 1062.
Due to the constant Arabs riots, around the IX – X century AD, Bosa was completely rebuilt on the opposite bank (right) of the rive, up to the slopes of the Serravalle hill, which in the thirteenth century was topped by the Malaspina Castle and by the original architecture of the historic district of Sa Costa.
After four centuries of Aragones and Spanish domination, in the ‘700 and ‘800, that is to say during the time of the Savoy, the city experienced a period of great turmoil and economic development. So along with the increase in crafting such as the leather, gold and silver, the shipbuilding industry for the production of small fishing and coral boats, the production of filet and filigree jewelery. All at the same the area also experienced a revival of cultural and artistic life.
Dating back to this time: the old buildings of Sas Conzas (The Tannery), officialy declared as Industrial Archeologic Monument in 1979, the church of the Carmine and the Cathedral of Santa Maria, in the Baroque and Piedmontese style, the Old Red Bridge and the Palazzata overlooking the riverr. Dating back to the same period of history, but with a building typology richest in decorations and ornaments, the noble district of Sa Piatta, whose eighteenth and nineteenth century aristocratic palaces are decorated with multi-faceted baroque friezes, capitals and architraves with bas-reliefs and balconies with elaborated iron wrought. Everywhere, and is like that not only in Bosa but also in the neighboring Planargia villages, the abundant use of local stone: the pinkish and reddish volcanic trachyte of Bosa.