
Recent excavations at La Piana, an Etruscan settlement of the 4th to 3rd centuries B.C. near Siena, have exposed a large circular vat with an interior diameter of about 4.5 m., located roughly at the center and highest point of the site. This feature is constructed of dry-laid field stones in two concentric cylindrical rings with a metre-wide cylinder of dense clay packed between them. This configuration brings the diameter of the whole to over 9 m. The feature was built into the main structure at the site, Building A, and was roofed. A central pillar of low-fired, porous bricks may have held up a roof that was constructed to trap and channel rainwater.
This paper presents the most recent hypotheses for the cistern's structure above ground and explores its relationship to numerous examples within a technology for which the Etruscans were well known, water management. Among all the hundreds of cisterns known from the Etruscan world, it is surprisingly difficult to find published parallels.