This is an ancient furnace located along the road that, from San Fabiano, leads to the Torre di Luciana Observatory, we are in the middle of the classic Chianti, in the beautiful countryside between Mercatale and the Testalepre woods. From here then, go up to Panzano in Chianti. After a few hundred meters along a dirt road, in front of the Castelvari farm, here is a partially collapsed ruin. It might look like an old house in ruins, but actually if you look closely you can see a certain conical shape. Part of it is blackened with smoke, almost looking like a huge chimney. It is a small furnace, which until the 1940s was used to obtain mortar from "strong stones" with a high content of calcium carbonate, such as Alberese, a material easily available in the area. In previous times it also produced clay materials.