In recent years, local activists in the Global North and South have been organizing to improve degraded and abandoned spaces in marginalized neighborhoods by creating parks, playgrounds, urban farms, or community gardens. This paper integrates existing knowledge on urban place attachment and sense of community with scholarship on environmental justice in order to understand the role of place attachment in environmental mobilization in distressed neighborhoods across political systems and urbanization contexts. It examines the different forms of connections that activists develop and express toward neighborhoods with long-time substandard environmental conditions and how their experience of the neighborhood shapes their engagement in environmental revitalization projects. This comparison of three neighborhoods in Barcelona, Boston, and Havana shows that activists in all three places intend for their environmental endeavors to express grief at the loss of community, fears of erasure, and emotional connection and feelings of responsibility to place. To address environmental trauma, they aim to construct nurturing, soothing, “safe havens,” recreate rootedness, and remake place for residents.