On 11th of December, UNESCO Global Geoparks celebrate the International Mountain Day. The Global Geoparks Network encourages all UNESCO Global Geoparks to join the celebration and promote their mountains, some of the most interesting geological features of UNESCO Global Geoparks, which create the conditions for a wide spectrum of life forms. Mountains are home to 15% of the world´s population and they provide freshwater for everyday life to half of humanity. About half of the world’s biodiversity hotspots are concentrated in mountains and mountains support approximately one-quarter of terrestrial biological diversity. Mountains are today under threat from climate change and overexploitation as we tend to forget that the mountains are important territories of biodiversity and life.The theme of this year's celebration is "Restoring mountain ecosystems" aiming, according to UN “to increase awareness about the relevance of mountain ecosystems and call for nature-based solutions, best practices and investments that build resilience, reduce vulnerability and increase the ability of mountains to adapt to daily threats and extreme climatic events”. (www.un.org/en/observances/mountain-day). Please send your activities and good practice examples, photos, videos.Join the conversation on social media using the hashtags:#GlobalGeoparksNetwork #MountainsMatte r #UNESCOGlobalGeoparks #sustainablemountaintourism