DETOUR TO FRASSINORO
From Rovolo you can reach Frassinoro through a route, been pointed out by the "Sentieri della luce" project, that is signposted but lacks marking on the map. The detour is on a cart road near Monte Uccelliera that leads directly down to Frassinoro and Casa Giannasi. The route is an open road used by vehicles as well, but the last stretch before reaching Terminaccio is not mapped; still, this is a useful and necessary route.
This is the most convenient way of including Frassinoro in the itinerary; from Frassinoro you can then reconnect with the Matilde Path by taking Via Bibluca until you reach Pietravolta. The path is on a cart road all the way and constantly used for agro-forestry work.
Walking time from Rovolo to Frassinoro: 1h 40'
Walking time from Frassinoro to Pietravolta: 1h 30'