Roman land division in Istria, Croatia: historiography, LIDAR, structural survey and excavations

Many interpretations of the ancient cadastre of the Roman colonies of Pola and Parentium on the Istrian peninsula in Croatia have been offered recently on the basis of satellite imagery and the Croatian topographic map. This grid, spreading continuously over an area of roughly 1200 km2, was identified through numerous structures which correspond to the ancient Roman metric system, but they were never a part of further research. This approach enabled identification of structures that were most often visible in the contemporary cadastre, like modern roads or field boundaries, but gaps were left in areas where the modern cadastre did not reflect the ancient one. Until the commission of airborne laser scanning (ALS or LiDAR), from which our research began, one of these gaps was on the northern side of the Lim bay, in the Municipality of Vrsar. Interpretation of ALS data resulted in detecting different, multi-temporal spatial organisations of the landscape, among which were numerous, previously unidentified, remains of the Roman limites. The results of this interpretation guided the field inspection. Different surface manifestations of individual remains were categorized, and it was defined which are the original Roman structures. The results of this structural survey subsequently guided the archaeological excavations. Only with the combination of these procedures it was possible to understand the original construction of the limites.