The Torre Luciana Astronomical Observatory represents an example of collaboration, finalised at educational activities, between public authorities and private concerns. The building is owned by a company that produces concrete which, in 1992, restored its early medieval structure (a Longobardic castle). Granted up to 2003 for use free of charge to the University of Siena, which had destined it, as Astronomical and Naturalist Observatory, to the Faculty of Mathematical, Physical and Natural Sciences, it is currently managed by the Commune of San Casciano. Equipped with good instrumentation, it also carries out educational and informative activity thanks to the collaboration of a group of amateur astronomers.