Apart from being the administrative centre during the long Venetian government, Serina’s fame grew with the important trade route that passed through it, only to decline again when the route was closed in 1592 because a new road (Via Priula) had been opened up. The original route was the via Mercatorum, a riding route climbing from Bergamo to Nembro and Selvino, then descending again to Rigosa, Sambustia and Ambriola. As it crossed the Serina creek, the route climbed up to Pagliaro, Frerola, Lepreno and Serina. From here it went to Dossena, then on to San Giovanni Bianco and on up to Oneta, Cornello dei Tasso, Piazza Brembana, Olmo al Brembo, Averara and finally Valmoresca where it wound its way through what is now the San Marco Pass to arrive in Valtellina. In later years, as the population grew, a branch was built joining Selvino with Serina via Aviatico, Trafficanti, Tagliata, Nespello, Costa Serina and Cornalba, a circular route which today is a beautiful nature walk.