The Church was built in Romanesque Gothic in particular is to highlight the splendid portal. Built in the twelfth century, it was restored and enlarged in 1494. Here comes a splendid historical events linked to the discovery of one of the nails of the Passion of Jesus: after the conquest of Jerusalem in 1099, an archbishop Teutonic said Allemann, who had taken part in the First Crusade, came into possession of one of the nails of the cross of Jesus. On the way back home, arrived in Como to go up the Lario, ever to Germany.
Allemanno he decided to seek refuge in Torno, because it was not affected by the riots of Como. After spending the night, resumed the next morning browsing, but was blocked by a heavy storm sudden. When the storm subsided, he wanted to continue his journey, but yet another strong storm gave him no respite, and so on, until the bishop did not realize that these were clear signals divine, that suggested to lay the relics on the site and specifically in beautiful Church S. Giovanni.