Eastern South Asia is . Bangladesh has a tropical monsoon climate. The Sundarbans in Bangladesh, which is shared with India, is a UNESCO world heritage site. Cox's Bazar Beach is one of the world's longest beaches. Bhutan is roughly the size of Switzerland. It is located on the southern slopes of the eastern Himalayas, landlocked between the Tibet Autonomous Region to the north and the Indian states of Sikkim, West Bengal, Assam, and Arunachal Pradesh to the west and south. The land consists mostly of steep and high mountains crisscrossed by a network of swift rivers, which form deep valleys before draining into
Ecology of the Himalayas over a distance of at the Main Central Thrust fault zone, where the Greater Himalaya begin. Above the broadleaf forests, between , are temperate coniferous forests, likewise split by the Gandaki River. The western Himalayan subalpine conifer forests are found below treeline in northern Pakistan, Jammu and Kashmir, Himachal Pradesh, Uttarakhand, and western Nepal. The eastern Himalayan subalpine conifer forests are found in eastern Nepal, Sikkim, Bhutan, and Arunachal Pradesh. Along the border between Arunachal Pradesh and Tibet, the eastern subalpine conifer forests mix with the northeastern Himalayan subalpine conifer forests. East Himalayan Fir, West Himalayan Spruce, and Himalayan Hemlock