Switzerland is one of the most important countries in Europe in terms of cargo transit. Each year 26 million tons of cargo is transported through Swiss Alps by railways, of which 80 percent is transit cargo. Switzerland wants to promote more efficient, ecological and space saving means of transport. Gotthard Base Tunnel is thus a key project of swiss transportation policy. By constructing railway infrastructure, Switzerland has proposed an alternative to road passenger and cargo transport through the Alps. Tunnel construction enables integration of Switzerland in Europe’s high-speed rail network. Gotthard Base Tunnel has been officially opened on 1st of June 2016 and is considered as one of the greatest engineering achievements of 21st century. Total length of the tunnel is 57 km which surpasses Seikan tunnel in Japan by 3 km in length, which held the record up to this point. It is a high-speed railway tunnel that connects two swiss towns of Erstfeld and Bodio. Trains can reach speed of 250 km /h. The paper describes decision making process for construction of such tunnel, preparation of project documentation, technical characteristics of the tunnel including the high-speed track structure and finally the construction process of the tunnel. Further, aspects of maintenance through exploitation period and implemented safety features.