Ecological transition cannot take place without a territorial governance that also draws on its own spatial vision and without “vast area” authorities capable of pursuing it. The aim of the paper is therefore to argue this thesis using an approach that is not merely analytical-descriptive, but also historically-critical and design-oriented. Over the last century, important reflections on the urban-territorial archetypes have been carried out making it possible to rediscover today, in an era of great crisis of meaning and references, models on which to reflect in order to address spatial processes for ecological transition. On the shoulders of those giants rests the vision of Ecopoli which is developed below.