The Triangolo Barberini near Palestrina: contributions to knowledge about a unique and little-known worck from the seventeenth century, on the borders of the Campagna Romana

The Barberini Triangle in Palestrina is a very peculiar building attributed to Francesco Romano Contini. It has been built around the half of the XVII century near the town grown over the remains of the ancient Praeneste, along the axis called Olmata wich derives from an ancient Roman centuriation. This building, probably a suburban “casino di delizie” (a small building used as a place of recreation), stands out because of its planimetric matrix, an equilateral triangle related to an hexagon, and for the uncanny features of its plastic and sculptural decorative details (the so called gendarmi at the summit) even if they have only partially survived the degradation subsequent to decades of abandonment. 2. The Barberini Triangle has rarely been object of interest in the literature. Short Hints about this building, in Architectural History’s studies, are mostly found for the peculiar geometric matrix evidently related to the coeval Borromini’s “Chiesa della Sapienza”. There are some studies of local history, most of all trying to determine probable hypoteses about its origin, but they are confusing and misleading. It’s important to underline the lack of reliable surveys from both sides: they were absolutely absent and there were no reconstructions (or hypotesis about them) of what has been lost or damaged. 3. This research has been conducted on two fields. The first one has been the reliable survey on the building and its surroundings. The most recent techniques have been used and there has been the integration of historical cartography analysis and of existing representations. Results have been added to studies of geometric matrices eventually based on return charts even compared with some other structures, actually built or only theorized, presenting analogue features. To complete, a reconstructive modeling conducted with philological criteria has been performed. On the other hand, there has been the need for necessary reorganization and clarification of yet known bibliographical and historiographic data, confusing and misleading as pointed out before. All these aspect, unpublished to date, are presented here for the first time. 4. The deep knowledge of the artefact deriving from survey has been the first requested and accomplished goal. The model helped for a reliable reconstruction of many peculiarities of this building, that have been only partially analyzed and only with elementary graphic analysis deriving from not truly accurate metric-morphological data. There has been investigations about the Triangle relation with the surrounding building complex and, on a larger scale, with the territorial and enviromental context. This contribution is a call to attention about this architectural work that is unique in many ways, little known in literature, and that has never been surveyed with accurate criteria and subsequently never analyzed for the proportional-geometric features defining its morphology. This essay has been conducted to underline the need for immediate interventions, without wich the Barberini Triangle risks a total decay.