Today the former "Iron Curtain" forms the "European Green Belt", an important corridor within the trans-European Network for Green Infrastructure (TEN-G). Its continued implementation and development requires a solid basis for decision-making in order to derive spatial and temporal priorities for future corridor development. Employing spatial data and suitable methods of GIS analysis, the project will generate base data to assist the continued development of the Green Belt. Available GIS-data on existing protected sites will be processed and harmonised (i.e. inventorised) for the Central European section of the Green Belt (Baltic Sea – Adriatic Sea). Building on this, methods developed within the EU-Interreg-Project TransEcoNet will be applied to analyse the level of connectivity (i.e. the interlinking of adjacent protected sites). An analysis of gaps will be undertaken, whereby the pinpointed gaps will be prioritised. Subsequently, recommendations for action will be derived in order to raise the level of connectivity. The area lying between the intersecting border point of the Czech Republic/Slovakia/Austria and the intersecting border point of Hungary/Slovenia/Austria will be taken as a pilot region.