At the end of the eighteen hundreds, the railway ended the isolation of the Alps with the drilling of the first tunnels, drawing two mountain faces closer than ever before.
An emblematic example is the Frejus tunnel, which was constructed when Savoy was part of the Kingdom of Sardinia, to improve internal communication which, during the winter months, was stalled. Work was completed in 1871 after the establishment of the Kingdom of Italy and the passage of Savoy to France: the railway line was international at its inception.