Brenner Base Tunnel
The Brenner Base Tunnel (German: Brennerbasistunnel; Italian: Galleria di base del Brennero) is a 55-kilometre-long (34 mi) railway tunnel under construction through the base of the Eastern Alps beneath the Brenner Pass. Once completed, the Brenner Base Tunnel will rank as either the second or third longest railway tunnel in the world, depending on the definition employed.