The Sassi are the historic city of Matera and form a complex urban center. The Sassi of Matera were entered in the list of "World Heritage" by UNESCO in 1993. The inscription was motivated by the fact that they represent an extraordinary urban ecosystem, capable of perpetuating the more distant past Prehistoric way of living in caves up to modernity, a unique example of careful use in time of natural resources: water, soil, energy. Derived from various forms of civilization and human activity occurred over time: from the Prehistoric, the entrenched villages of the Neolithic period, the habitat of the Eastern civilization rock matrix (IX-XI century), which is the substratum of urban Sassi, with its trenches, pipes, tanks; until the Norman-Swabian civitas matrix (XI-XIII century), with its fortifications, and subsequent Renaissance expansions (XV-XVI century) and Baroque city accommodation (XVII-XVIII century). Finally, sad example of social degradation and hygiene of the nineteenth and the first half of the twentieth century, until displaced placed in the '50s, with the consequent recovery. Sasso Barisano, the center of the old town, is the richest and friezes carved portals; Sasso Caveoso, looking instead to the south, is arranged like a Roman amphitheater, with the cave dwellings which descend in terraces, and perhaps takes its name from the quarries and classical theaters. At the center, the Civita, rocky outcrop that separates the two Sassi, on top of which is the Cathedral. On the opposite side of the Gravina of Matera, the Murgia plateau, which acts as a natural backdrop, with numerous rock churches scattered along the slopes of ravines protected by the institution of the Park of the Murgia Materana: Renaissance and Baroque facades open onto tanks of VIII century, transformed into homes. Byzantine churches hide wells dedicated to the cult of Mithras. The Stones were set major film productions.