Rings of the Five Lakes | Stage 3 Cascina Tonino - Poggio Montresco

A smoother, a grinder and an axe were found in Bienca; the tools are made of dark stone, a material that was certainly used abundantly until the Roman conquest due to the scarcity of metals. An element of great importance is also the large erratic gneiss boulder with two intrusions of granatiferous calcite (soapstone), placed behind the votive shrine in Casale Montresco, in Bienca. It has in fact thirty-six engravings on the south side, 5 to 12 cm long and 0.5 to 1 cm deep, many of them in a "V" section, probably used for sharpening stone axes. Boulders with such engravings are rare in these areas while they are more frequent north of the Alps. The main find belonging to Roman times is the aqueduct canal, which crosses the area in a north-south direction. The work started in the Maresco di Bienca, perhaps collecting the waters coming from Andrate. The external part is made of split stones and mortar, the inside is made of opus signinum (crumbled brick mixed with lime). An important aspect of the construction technique is the lowered arched vault, built with stone ashlars alloyed by lime. There is a remarkable limestone tank, to allow the deposit of impurities. It is 5 m long and 2 m wide, with a depth varying from 1 to 2 m. Many sections remain visible, several complete, others reduced to a few stretches of wall that are indistinguishable from the walls separating the properties.