The UNESCO World Heritage (WH) Site Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe represents the most complex transnational serial natural site in the UNESCO portfolio - comprising 78 component parts in 45 protected areas (PAs) in 12 countries. The programme area shares almost 25% of the components parts distributed in 5 countries (AT, DE, HR, SK and SI). While local management units of the component parts face similar challenges, i.e. concerning buffer zone management, the respective environmental and socio-economic contexts differ considerably on local and national level. The main project objective is to improve management quality and effectiveness of the WH site to safeguard the ecosystem integrity of the single component parts by improving capacities and active participation possibilities of relevant stakeholders. The project takes an ecosystem-based and participatory approach working on different administrative levels to anchor the WH site in sustainable regional development and produce replicable and innovative models for WH beech forests and their local surroundings (i.e. WH Beech Communities, sustainable buffer zone management, Beech Forest Quality Standard). The main outputs are guidelines and strategies for stakeholder participation and regional development, a handbook for buffer zone management, recommendations for visitor management, a communication concept and a Beech Forest Quality Standard that support protected area administrations, public authorities and actors from civil society in their daily work. The results will be applicable for other WH component parts outside the programme area. The transnational cooperation responds to the challenges of a transnational WH site, as comprehensive solutions must reflect the heterogeneity of the single component parts. Further, it ensures the establishment of a WH-wide learning network between different stakeholders that would not be possible on national level.