Passo San Giacomo starts from Riale, a small town above the Toce waterfalls in Val Formazza. It is just under 10 km long, the slopes are never impossible, but there are long stretches at 9-10%. The bottom is very stony, you need a good amount of training to climb. At an altitude of about 2100 meters you will find the "Maria Luisa" Refuge from which there are still about 200 meters of difference in height to get to the pass. Once you get to the pass you are almost in Swiss territory and just go a few hundred meters to cross the border.