The Italian side of the Splügen is the one that makes people swear with happiness. From Campodolcino the road climbs the Valle Spluga in a rapid string of tight hairpins, stacked one above another up the valley wall, past waterfalls and a gorge that the old road builders had to blast through. At the top, at about 2,114 metres, you arrive at the border, a modest customs building and the long, cold Lago di Montespluga, held back by a dam and glinting in a bare landscape of grass and stone.
The road you are riding was built in the 1820s by the engineer Carlo Donegani for the Austrian government, which then ruled Lombardy and wanted a better link to the north, and the route is far older than that. Merchants, armies and mule trains have crossed this gap for two thousand years, and the Roman and medieval trade routes ran very much along the same line. The Swiss side drops into the Rheinwald and the old village of Splügen, with stone houses and a small square that has hardly changed in centuries.
On a bike the Italian hairpins are tight and require patience, with some narrow tunnels and gallery sections that are damp and echoing. The surface is generally good but can be patched, and in early summer there may be gravel from rockfall. Traffic is moderate, and the road is closed in winter, usually from about November to May. At the top, expect a stiff wind, snow patches into June, and temperatures that can be low even on a bright day.
Fuel is a real issue. There is none at the top, and Montespluga has only a few buildings. Chiavenna, on the Italian side, is the nearest large town, about twenty kilometres down the valley, with all the services, and Splügen on the Swiss side has some. Fill up beforehand, and enjoy a coffee at the little cafe by the lake if it is open. The best light is in the morning, when the valley is still in shade and the lake is calm.