The construction of tunnels involves the resolution of various complex technical problems depending on the geological and geological-environmental context in which the work fits. Only a careful analysis of all the geological and geological-environmental issues and a correct reconstruction of the conceptual model can lead to optimal design solutions from all points of view (including financial) and ensure the safety of workers during the construction and users in the operation phase. It was therefore felt that there was a need to collect in one volume the state of current knowledge about: all the geological and environmental issues related to the construction of underground works the different methodologies used for the reconstruction of the conceptual model the different risk typologies that it is possible to encounter or that can arise from tunnel construction, and the most important risk assessment, management and mitigation methodologies that are used in tunneling studies.