FROM CULTURAL HERITAGE TO SUSTAINABILITY: ARCHITECTURES AND NATURE-CITY

.Firstly we would like to display the problem and our hypotheses, which contain the solutions to the problem on which we work as architects acting on the city. Everyday in the world entire towns disappear from the sight of official economies together with their well-being measures and they go in stand by. Some of them are completely destroyed, others simply stop in a sort of hibernation, and wait like messages in a bottle for a future economical-ecological science to understand them, heal them and bring them back to life. This phenomenon of stand by of the city from a certain point of view looks like a paradoxical aporia, but from another helps us go nearer to the heart of architecture: when things stop and stick to a beautiful order that goes beyond an ephemeral time, then there is Architecture. In this situation we must study the ancient centres in order to understand their cultural heritage and use it for the new architecture. In conclusion we can say that in between the old which is fading away, and the emerging new, we find the condition necessary for the cultural and environmental heritage which creates the sustainability of the development. The study concerning the process of recovery of urban depressed areas led to the partlyunexpected discovery of the nature-city. It would not be correct to use this synthetic definition referring only to small towns or villages as ecosystems with unused or wasted resources as their own powers of sustainability; we could use it wherever the conditions of existence of the nature-city are. Even in big unsustainable metropolis (where our study becomes even more interesting). This is the most innovative aspect of our research: it is possible to say that the nature-city is called so because its relationship with nature, together with the complexity of adaptation to human civilization, is the basis of its very existence and richness. This is evident in its physical structure: in origin there can be a dominant natural entity (like a river, a lake, the sea, a forest, a mountain or a gravina). Together with one or more of these strong natural entities there is an inhabited centre. Then both the entity and the centre will evolve themselves together