The work to build the longest train tunnel in the world began 17 years ago, and on June 1, 2016 the Gotthard Base Tunnel will have its opening ceremony. The train in the tunnel will begin service at the end of the year. The $23 billion tunnel is just over 35 miles long and it will take about 20 minutes to travel from one end to the other at the maximum speed of about 155 mph. It will take about 30 minutes to travel from Switzerland to Milan.