The Indus River (Sanskrit: सिन्धु Sindhu; Urdu: سندھ Sindh; Sindhi: سندھو Sindhu; Punjabi سندھ Sindh; Avestan: حندو Hindu; Pashto: ّآباسن Abasin "Father of Rivers"; Persian: Nilou "Indigo Waters"; Tibetan: Sengge Chu "Lion River"; Chinese: 印度河 Yìndù Hé; Greek: Ινδός Indos) is the longest river in Pakistan and the twenty-first largest river in the world in terms of annual flow. It is often considered the life-line of Pakistan by the people of that country. The Europeans used the name "India" for the entire Indian Subcontinent based on Indos, the Greek appellation of this river. Originating in the Tibetan plateau in the vicinity of Lake Mansarovar, the river runs a course through Ladakh district of the state of Jammu and Kashmir in India and the Northern Areas (Gilgit-Baltistan), flowing through the North in a southerly direction along the entire length of the country, to merge into the Arabian Sea near Pakistan's port city of Karachi. The total length of the river is 3,180 kilometres (1,976 miles). The river has a total drainage area exceeding 1,165,000 square kilometres (450,000 square miles). The river's estimated annual flow stands at around 207 cubic kilometres. Beginning at the heights of the world with glaciers, the river feeds the ecosystem of temperate forests, plains and arid countryside. Together with the rivers Chenab, Ravi, Sutlej, Jhelum, Beas and the extinct Sarasvati River, the Indus forms the Sapta Sindhu (Seven Rivers) delta in the Sindh province of Pakistan.