The environment is often a crucial determinant in war. While research on environmental peacebuilding indicates that environmental factors can facilitate cooperation after the end of hostilities, it remains relatively unexplored in a transboundary setting. Drawing on insights from political ecology, this article asks, how can environmental conservation contribute to the establishment of sustainable peace in a transboundary post-conflict context? Using the Balkans Peace Park Project (B3P) as a case study, it investigates the advantages and disadvantages of community-based conservation between Albania, Kosovo and Montenegro, and examines the potential of shared environmental issues to foster an ‘imagined’ regional community. The analysis reveals that community-based conservation provides the necessary vehicle to enhance sustainable peacebuilding, but requires local capacities to match the actions on the national and supranational levels. It also finds that the ideal of a new regional identity B3P seeks to foster is an exogenous one and explains the relative lack of local support. Nonetheless, it does provide the grounds for an alternative reality in the border region. The study concludes by highlighting that institutionalised communication and information sharing, as well as environmental education and awareness are crucial to support successful environmental peacebuilding through community-based conservation.