Abstract
Twelve polychrome floor mosaics were found in a third century AD public building in Zippori, Israel, including one of extraordinary quality representing Nilotic scenes. Conservation of the mosaics was carried out in situ as part of a broader project directed by the National Parks Authority of Israel. The public was allowed to watch the conservation work as it happened. This paper describes the treatment of the mosaics: starting with the technical procedures, it then considers the principles and the objectives behind the choice of the methods followed and concludes with some general observations.