Nepal, officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia with a population of 26.4 million. It is a multiethnic nation with Nepali as the official language. Kathmandu is the nation's capital and largest city. Nepal has a very diverse geography, rising from less than 100 metres (328 ft) elevation in the tropical Terai—the northern rim of the Gangetic Plain, beyond the perpetual snow line to some 90 peaks over 7,000 metres (22,966 ft) including Earth's highest Mount Everest or Sagarmatha at 8,848m (29,029 ft). Nepal is a landlocked country in Southern Asia, between the Tibet autonomous region of China and India. It contains 8 of the world's 10 highest peaks, including Mount Everest - the world's tallest - on the border with Tibet, and Lumbini, the birth place of Gautama Buddha, the founder of Buddhism. A monarchy for hundreds of years, Nepal was declared a republic in June 2008. Nepal has a Monsoonal climate with four main seasons - though traditionally a year was categorized into six distinct climate periods: Basanta (spring), Grishma (early summer), Barkha (summer monsoon), Sharad (early autumn), Hemanta (late autumn) and Shishir (winter).