(E)co-existence originates from participation in the seventeenth edition of Europan, where the project created for the Swedish city of Piteå received a special mention, achieving third place. This success provided an opportunity to delve into urgent issues such as climate change and the necessary transformation of cities in response to it. The aim of this thesis is to explore the theme of climate adaptation of urban settlements through the use of nature and biodiversity, understood as tools for adaptation and mitigation. The work concludes with the development of a set of strategies and actions useful for the transition of European cities into places where humans can continue to live and operate in prosperity, coexisting harmoniously with nature and other forms of life.