The village of Asso, administrative seat of the Valle Assina or Vallassina to which it lends its name, is located at the confluence of the valleys of the upper Lambro, in a strategic position at the centre of a basin which connects to the north with Civenna and Bellagio and to the south with the far edge of the Larian Triangle. At the end of the 1800s, its scenic beauty, which made it a favoured tourist destination for the Milanese, combined with its importance in the valley as a manufacturing hub (consider the Ottolini textile mill, still active today), increasingly emphasised the importance of a direct link with Asso.

The train reached Erba as early as 1879, but the final section had never been constructed, leading to the local saying: "Quant la légura la fa 'l tass / la végn la feruvìa a Ass" ("when the hare plays the badger, the railway will come to Asso").
On15 June 1922 the long-awaited Erba-Asso section opened, along with its terminus station. Its location, within the municipality of Canzo but on the edge of its border with Asso, was the subject of many disputes between the inhabitants of the two towns, already renowned for their legendary quarrels: hence the name Canzo-Asso.