The Bavarian Forest National Park (BFNP) and Šumava National Park (ŠNP), established in 1969 and 1991, respectively, are located between Prague and Munich. Their long common border accents the transboundary issue regarding nature conservation, ecological corridors and connectivity. Plans to protect this large forest landscape, dating back to the early twentieth century, were never implemented due to the two World Wars and Iron Curtain. Initially, there were many joint activities. Many common projects (e.g., joint information centre, transboundary public transport system, GPS lynx and deer telemetry) were conducted. Both sides have learned a lot during these 25 years of cooperation. The main obstacles in cooperation are economic differences between the regions, language barriers and different policies and laws. There is only one common ecosystem of mountain forests, common populations of lynx, capercaillie or bark beetle, and the partners have to learn how to share their common responsibility for the future.Step by step, the transboundary cooperation is improving, which is very important in good years, but maybe even more important in bad years. The principle stance of the transboundary partner can buffer threatening in the neighbouring national park and support recovery when the crisis is over.