A special stamp to commemorate the centenary of the opening of Sempione Tunnel (Simplon Tunnel) was issued on March 18, 2006. Simplon Tunnel is the longest rail tunnel in Europe. The tunnel is also known as Sempione Tunnel (or Italian Passo del Sempione). The tunnel was the longest in the world when it was built (i.e., 19.8 km long) links Italy to Switzerland..
Sempione Tunnel (2006)