Paper to be presented to the Cultural Heritage Istanbul Congress 2011 Authors: Title: Marcella Frangipane, Francesca Balossi Restelli, Giulio Palumbi "Arslantepe-Malatya: Conservation and exhibition of a prehistoric monumental site" Key-words: Mud-brick architecture conservation; communication; Arslantepe. The paper will present the pioneering project of conservation and exhibition of the 4 th millennium palatial complex at Arslantepe-Malatya, which has been recently realized (in May 2011) in the form of an open air museum. The protection of the monumental buildings in mud-bricks, with walls standing for more than 2 m., the still preserved original white plaster, in some places decorated with wall paintings, has been an ambitious and difficult task, combined with a thorough study aimed at exhibiting in a proper way what these unique monuments tell us of the history of humankind, sharing the main achievements of the scientific research with a vast public. The main purpose therefore was not only to protect and illustrate this extraordinary architecture, but also to make people conscious of what these buildings, and the materials found in them, may represent for the understanding of the formation process of an early State society, in other words the foundations of modern society. The project has been characterised by four main purposes: 1) not to damage the underlying structures and levels; 2) to protect the structures from water and humidity and any other climatic stress; 3) to create a correct perception of the monument as it was; 4) to transmit a correct and effective message to the public, leading the visitors to perceive and understand the new historical and anthropological knowledge achieved in the site through a long lasting archaeological work.