The article is about the Urban Ecomuseum, a contemporary art process initiated in 2021 in the city of Porto Alegre, Brazil. This experience in the field of art reflects about city and ecology, weaving relationships with cultural and natural patrimony and urban transformation. In the writing, one of the axes that make up the experience of the Urban Ecomuseum is presented, starting with the planting of an individual tree, which triggers the beginning of a series of plantings in public squares, constituting an open-air pathway in which people can look at this living collection at the same time that they are encouraged, when walking through the city, to look at the landscape that continually transforms itself.