This story appears in the March 2011 issue of National Geographic magazine. When the Welsh chronicler Adam of Usk traveled over Switzerland's wild and remote Gotthard Pass by oxcart on his way to ...

Switzerland’s Gotthard Base TunnelExternal link is the world’s longest (and deepest) railway tunnel. Opened in 2016 after 17 years of construction, it consists of two 57.1km single-track ...