The Bisagno is the most important stream that crosses the city of Genoa. It is not really a river, but rather an unadorned and unpredictable torrent, sadly known in most recent years for the destructive strength of its floods. But this is modern history. For a long time, the Bisagno has played a significant role in the city life; an entire and important city district is called “Foce” (meaning river mouth) because it is located where the stream ends into the sea, and the Genoese greengrocers still bear the traditional nickname of "bisagnini", because once fruit and vegetable were grown in small gardens on the stream banks.
The Bisagno rises at the Scoffera Pass and flows through the municipality of Bargagli, which it separates, as a natural border, from that of Davagna. At the Scoffera Pass, one can walk down the slope toward the ditch, where the stream rises, and, when the rough signs of the (un)civilized world (represented by the abandoned trash) disappear, penetrate into a thick and dark wood, along the tiny brook in whose puddles one can discover the gray freshwater shrimps. Then the course of the Bisagno follows that of state road 45 that first crosses Bargagli, and then Traso. This last village is worth a visit; it is spread in the vertical direction, stretching from 300 to almost 600 meters upon sea level. At the higher elevation, close to the last house of the village, an easy and tidy footpath takes inside the chestnut wood; following this path, in half a hour, one can reach the ruins of Barego, the old village, which was abandoned more than 50 years ago and is by now in complete downfall. The visit is fascinating, but it may be dangerous, because the ruins are tottering and entirely covered by thorny bushes.
At 'La Presa' the Bisagno joins to another stream, the Lentro, coming from the valley which bears the same name; this is the starting point of the ancient aqueduct, which supplied water to the city of Genoa.