Bhutan is a landlocked South Asian kingdom in the Eastern Himalayas, bordered by India and China. Known as the "Land of the Thunder Dragon", it is famous for measuring its success through the philosophy of Gross National Happiness and being one of the world's few carbon-negative countries. Bhutan encompasses a territory of 38,394 square kilometres (14,824 sq mi) and features a dramatic topography that ranges from lush, subtropical plains in the south to sub-alpine Himalayan peaks in the north. Because over 70% of the land is preserved as forest, the country supports highly diverse ecosystems.  Bhutan is the world's last remaining Vajrayana Buddhist country, with Buddhism serving as a central pillar of the society and constitution. A significant Hindu minority is also present.