<p><strong>Abstract.</strong> In July 2017, the system of Bergamo City Walls was registered in the UNESCO World Heritage List, together with other Venetian fortresses in Italy, Croatia and Montenegro. This important historical document needs continuous care and caution in order to be preserved complete, despite the continuous atmospheric and anthropic attacks, giving rise to dangerous deterioration processes on the artefact. The UAV photogrammetry is a suitable surveying method for such an extended system, able to collect all the geometrical, material and deterioration information needed for an effective maintenance program, also quick enough to allow for a repeated monitoring of the entire wall circuit. This paper presents the UAV survey campaign planned, and partially already completed, in order to test the methodological choices and solve all the operational difficulties to use drones in an urban environment, mainly because short distance shooting of nearly vertical surfaces was required.</p>

<p><strong>Abstract.</strong> Photogrammetry is a survey method that provides good quality results also by using basic photographic equipment and user-friendly, low-cost software. The advantages of the image-based modelling techniques compared with the traditional topographic tools are very significant in emergencies, when the time for the survey is limited and many buildings are involved, as usually happens in case of relevant seismic events. The goal of this study is to verify the quality of the models obtained from quick digital images acquisition, carried out under non-optimal lighting condition and no accessibility of the building. As case of study was chosen the main front of Villa Galvagnina in Moglia, a Renaissance hunting palace badly damaged by the earthquake of May 20, 2012. The modelling was performed using two different software, Agisoft Metashape and 3DFlow Zephyr. This paper presents a comparison between the results obtained using different datasets; the workflow, the difficulties encountered during the survey and the data processing methods are fully described and discussed.</p>

<p><strong>Abstract.</strong> The historical and cultural relevance of the City Walls built by the ‘Serenissima’ Republic of Venice in the second half of 16th century was recognized in 2017 by the insertion of Bergamo, together with other Venetian Fortresses in Italy, Croatia and Montenegro, in the World Heritage List of UNESCO as transnational site. In the framework of the nomination to the WHL, the City Council together with the University of Bergamo started a campaign of studies and surveys aimed to prepare a conservation planning. The goal of this plan is to assure a constant monitoring of this artwork, so that a strict routine of controls, cleaning and small strengthening works would prevent more relevant interventions, which could corrupt the material integrity of the building.</p><p>This paper delineates the methodological and operational workflow applied to the preparation of the maintenance plan, now in progress, for the Venetian City Walls of Bergamo, where the photogrammetric survey by means of UAV plays an important role. The different working phases, the adopted instrumentation, the difficulties encountered and the choices made are described, and some case studies are also illustrated that represent well the typical problems encountered for the conservation of the Walls.</p>

On May 20, 2012, an earthquake of magnitude ML = 5.9 hit a vast area of the Po Valley, in the territory across Lombardia, Veneto and Emilia, with the epicentre close to Finale Emilia. The seismic event, unusually intense for the area, caused extensive damage to the built heritage, so that six years later many buildings are still waiting for the necessary restoration works. One of them is the Villa Galvagnina in Moglia, in the province of Mantua. The damages caused by the earthquake made necessary emergency strengthening works. Alongside these emergency measures, the Local Office of the Ministry of Culture considered suitable to start more detailed studies on this neglected asset. The present study is part of the Superintendence initiatives, concerning the mapping of the building materials, a survey about murals' decay, as well as the damage and crack patterns. The aim of this data acquisition campaign is to identify the main risk factors for the preservation of the villa and to identify possible strategies for the strengthening and conservation works. The article critically presents the working method adopted for the survey setting up. The data acquisition steps, the difficulties experienced, and the choices made are fully described and some preliminary considerations are also expressed on the main damage suffered by the villa and on the ongoing deterioration.

The implementation of architectural heritages' information systems to collect a huge amount of data using BIM and GIS constitutes a relatively recent field of research. However, the potentiality of such an approach is clear: the systemic application of these tools to the sites belonging to the UNESCO World Heritage would allow the building of easily accessible databases to support the heritage sites' management and preservation. As part of the collaboration between the Municipality and the University of Bergamo, an information system has been designed to support the Preservation Program of the Venetian Fortress of Bergamo. The geometrical simplicity of its elements makes the complex a suitable case study for the development of a data digitization procedure, allowing an efficient management of ordinary maintenance and, where needed, a detailed representation of the state of conserva- tion, structural instabilities, and stratigraphic relationships, which can also be proposed in other contexts.