Build the Gotthard Tunnel is a decision available to 
Switzerland. It builds the 15 kilometer long Gotthard Tunnel.
It requires that Switzerland has invented Machine Tools and owns the province of Lucerne (ID 606). Switzerland owns the province in the beginning of the game. It gives 4 levels of railroad in Lucerne as well as 10 prestige. Illogically the decision doesn't actually require you to have researched any level of railroads, and the decision can actually give a higher level of railroad, than would be possible to build with the current technology.