The historic centre of Bologna is characterized by the presence of porticoes: the introduction of this architectural feature goes back to the thirteenth century, and is still present today for an extension of almost 40 km. Porticoed streets are then an important heritage of the town, that witness an unique architectural and artistic evolution of the city over the centuries: the constant presence of this architectural type forming a cultural, economic and aesthetic system made Bologna's porticoes valuable for its inclusion in 2006 in the Italian Tentative List of the UNESCO World heritage sites. A possible extensive documentation of this cultural complex is allowed by the recent advantages of IT, in particular photo-modelling tools, since they speed surveying activities, providing textured reliable 3D models and keeping in the meanwhile a low cost of the tools needed for data acquisition. The aim is not just bound to the creation of a virtual repository whose main purpose is fostering intervention on the historic buildings, ensuring their protection: the wider focus of 3D surveying activities is dissemination and sharing of digital contents within a vast audience.