It is the shortest petal, with a difference in altitude of more than 200 metres. The loop track diverges from the blue petal and it connects again with it between San Grato in Vicoforte and Bicocca di San Giacomo. It is 4.5 km long and the lowest altitude is in the town of San Michele at 450 metres a.s.l. Along this track it is possible to reach at least three worth visiting chapels in addition to the Parish church of San Michele Arcangelo, located under the steep rise in the hamlet of Castello, where there are still the ruins of the ancient castle. The famous Battle of Bicocca, between Napoleonic soldiers and the Piedmontese Army took place here on 21th April 1796.