The PLIS called Parco del Fontanile di San Giacomo has been established by Decision n. 240, July 6th, 2005 of Provincial Executive Council. The whole Park belongs to the municipality of Gerenzano and it covers about 413 hectares. It also includes areas owned by both the Park Authority and private citizens, that are used for agricultural purposes or as woodlands. Among the areas owned by the municipality two of them are particularly remarkable thanks to their particular naturalistic features: one is the the karst spring (with a surface of more than 17 hectares), that is a semi-natural structure situated south-east and created for irrigation purposes to exploit the waters cropping out with a constant temperature of -10° to -12° C. The other one is the Parco degli Aironi (with a surface of about 45 hectares) that was created after the environmental recovery of an old gravel pit and that has become an equipped park with play areas for children, training itineraries, tennis courts, and a building with toilets, rooms and porch for food service.