Which Swiss Alpine railway tunnel opened in 1882?

Which Swiss Alpine railway tunnel opened in 1882? The answer is the Gotthard Tunnel.

Opened for scheduled traffic on 1 June 1882, the tunnel runs beneath the Saint-Gotthard Massif between Göschenen in Uri and Airolo in Ticino. At about 15 kilometres long, it was the world's longest tunnel when completed and created a crucial north–south railway route through the Alps.

Construction began in 1872 under Swiss engineer Louis Favre. Workers excavated from both ends using compressed air, mechanical drills and dynamite, but faced intense heat, water inflows, rock instability and disease. The two headings met in February 1880 with remarkable surveying accuracy; finishing work continued before the railway opened.

The Gotthard Tunnel is often confused with the newer Gotthard Base Tunnel, which opened in 2016. The base tunnel is 57.1 kilometres long and runs at a much lower elevation, allowing faster, flatter trains. The older tunnel remains part of the historic Gotthard railway route and still carries rail traffic.