As cities grow and Earth becomes more congested with millions of miles of roads and railways, tunnels offer access to some of our last available space. They pass through massive mountains, beneath bodies of water, and even under large cities. This resource introduces readers to underground engineering and explains how it works in connection with other disciplines to solve problems of tunnel design, safety, construction, and sustainability. No doubt tunnels of the future will revolutionize transportation and address other global issues. This insightful resource will inspire readers to consider a career in engineering so they can help make it happen.