For the past 500 years the Last Supper has been considered a sick masterpiece: an invaluable treasure to be saved at all costs. In 1566, less than seventy years after its completion, Vasari despaired because what was left of this extraordinary work of art commissioned by Ludovico il Moro, was only a "blundering stain". At that time the many attempts at touching up, repainting and even covering the painting with oil and wax, made it very difficult to find the real Leonardo. The bombing of 1943 destroyed three walls of the church’s refectory, but once again, miraculously, the Last Supper was saved. Today, after twenty-one years and over seven thousand days of work, Leonardo da Vinci’s painting has been restored to its former glory with all its colours and intensity. The entire path leading to the refectory was renovated for the restoration work, undergoing some normative adjustments and service alterations. "Cestello"-type wall/floor appliances, specially designed and positioned along the longest sides of the hall, cater for all the necessary technical features: halogen lamps with reflectors incorporated for the general lighting of the space and frescoes, loud speakers serving service and information purposes, TV cameras for safety reasons, heat sensors, and signs. One single element closely tied to the "monastic" spirit of the hall and causing as little visual impact as possible provides for all the visitor services required, in complete accordance with regulations governing the proper conservation of the works on display.