Innovative application of Digital Twins and XR technologies in tunnel inspection and reparation resolves major challenges that are widely known for historic complexity of these tunnels. The era of conventional inspection techniques is marred by speed and insufficient coverage that ends up ignoring the fragile nature of these assets as a result. The XR technology and Digital Twin solutions provide revolutionized options, which comprise reshaping monitoring and boosting data integration. Digital Twins automatically develop real digital twins of the tunnels that enable monitoring in real time; predictive maintenance along with informed decision making. AR, VR, and MR are the major XR technologies that improve the accuracy of physical inspections because they superimpose virtual data over the real environment, which also contributes to learning more accurate inspection procedures and improving training simulations. To achieve this purpose, a system that combines XR technologies and Digital Twins has been constructed and tested in order to enhance the inspection process of heritage tunnels. This methodology highlights high-fidelity modeling and real-time information incorporation, with the system performance being evaluated for stability, correctness, and practicality. The results shed light on the fact that these tools have huge prospects to preserve and treat historic tunnels, as they are offered the opportunity to create (at least) digital twins, which could minimize structural overload in the real world. The paradigm shift in heritage conservation introduced by this way of thinking centers around the notion of using these historical buildings purely in their capacity as important cultural symbols for coming generations.