The ancient city of Nora was a Phoenician, Punic and Roman settlement rising on a peninsula in the south-west coast of Sardinia. Since 1990, our institution has been carrying on an interdisciplinary research project of excavation, architectural analysis, historical reconstruction and cultural promotion of tourism in this site. The excavations allow to specify and increase the knowledge of the middle Roman empire urban planning and to get a better understanding of the whole city and his history; the restoration of excavated monuments using gravels with different colours helps more than 60000 tourists every year to recognize the function of different areas. In spite of this, visitors are faced with serious difficulties in understanding a landscape of ruins with barely visible evidences. Thus a complete virtual reconstruction of ancient city has become essential. 3D models of Phoenician and Roman settlement have been developed, based on the reconstruction of ancient landscape (terrestrial elevation, bathymetry and shoreline) and reshaping archaeological plans produced in 25 years by universities that work in the site. Main monuments of the Roman city (forum, theatre, temples, domus, baths) and major crossroads have been rendered in greater detail, using sample-based textures that gives a photorealistic effect and implementing the models with furniture and decorations selected thanks to trustworthy source of information. 3D reconstructions are now available for tourist groups led by a guide in the Nora Virtual Tour: stereoscopic images have been rendered and uploaded in an app for mobile headsets that provide immersive virtual reality for the users. The guide controls the devices with a tablet using a Bluetooth connection: at the beginning of the visit, the tourists can view equirectangular panoramas of the ruins taken from a helicopter, than they are accompanied to hot-spots where the ancient monuments are shown in an evocative Roman reconstruction.