International Mountain Day is celebrated on December 11, 2017. The day was designated by the United Nations General Assembly in 2003, as they encouraged the international community to organize events at all levels on that day to highlight the importance of sustainable mountain development. The day is observed every year with a different theme relevant to sustainable mountain development.
FAO (Food and Agriculture Organization of the United Nations) is the U.N. Organization mandated to lead observance of International Mountain Day. The days aim is it to raise awareness about the relevance of mountain forests and the role they play within a Green Economy as well as in climate change adaptation measures. International Mountain Day adopts a different theme every year.
A mountain is a large landform that stretches above the surrounding land in a limited area usually in the form of a peak. A mountain is generally steeper than a hill. The highest mountain on Earth based from sea level is Mount Everest (8,848 m (29,029 ft)) in the Himalayas of Asia. The highest known mountain in the Solar System is Olympus Mons on the planet Mars at 21,171 m (69,459 ft). (With material from: Wikipedia)