Nepal officially the Federal Democratic Republic of Nepal,is a sovereign country in South Asia. It is mainly in the Himalayas, but also includes parts of the Indo-Gangetic Plain. It is the 49th largest country by population and 93rd largest country by area. It is landlocked and borders Tibet in the north and India in the south, east and west, while Bangladesh is located only 27 km (17 mi) from its southeastern tip and Bhutan is separated from it by the Indian state of Sikkim. Tourism is one of the largest and fastest-growing industries in Nepal, employing more than a million people and contributing 7.9% of the total GDP. Premier destinations include Pokhara, the Annapurna trekking circuit and the four UNESCO world heritage sites—Lumbini, Sagarmatha National Park (home to Mount Everest), seven sites in the Kathmandu Valley collectively listed as one, and Chitwan National Park. Most of Nepal's mountaineering earning comes from Mount Everest, which is more accessible from the Nepalese side. Nepal, officially opened to westerners in 1951, became a popular destination at the end of the hippie trail, during the 1960s and 1970s. The industry, disrupted by the civil war in the 1990s, has since recovered but faces challenges to growth, owing to a lack of proper facilities for high-end tourism termed the "infrastructure bottleneck", the flag carrier in shambles, and a handful of destinations properly developed and marketed.