underwater tunnel

An underwater tunnel is an engineering structure that allows transportation beneath bodies of water, such as rivers or seas. Built using reinforced concrete or steel, it involves drilling or excavating a passage through the substrate, then sealing and lining it to ensure safety and waterproofing. Vehicles, trains, or pedestrians can travel through these tunnels, providing efficient and direct routes across challenging water barriers. Examples include the Channel Tunnel between the UK and France. They are vital for minimizing travel time, connecting regions, and supporting economic activity, all while safely protecting the environment and water ecosystems.