In recent years, the availability of laser scanner instruments capable of operating over long distances (up to a distance of more than one kilometer with the most recent equipment) and the use of survey from drone has allowed us to extend this important methodology, once reserved for applications in the architectural field, the survey of dams
and relevant natural surfaces (banks and reservoirs ..). Thanks to these innovations it is now possible to carry out very accurate three-dimensional reconstructions of both engineering works and rocky slopes and slopes in general, as well as bathymetric surveys with an empty lake, from which various information can be extracted. These can be of various kinds, architectural, topographical (level curves, profiles, etc.) and geometrical (eg discontinuity, reservoir volume or unstable masses), etc. Thanks to the availability of a very detailed 3D digital model of the scanned surface, terrestrial laser scanner and UAVs represents very effective tools to accurately extract geometrical information from inaccessible structures and rock cliffs from afar. Comparisons between multi-temporal scans of the same surface can be helpful in monitoring surface displacements and detecting changes in surface features e.g. evolution of crack patterns, extent of deteriorated areas and/or with pathologies.