Source of the Amazon River the Mantaro. Explorers and scholars have identified each of the three rivers as being the source of the Amazon under one of the three definitions. The Mantaro is the most distant upstream point; the Maraňón is the main stem of the Amazon; and the Apurímac is the most distant source with an uninterrupted flow of water. The Amazon River is the largest river in the world in terms of its discharge into the Atlantic Ocean and either the longest or second longest river in the world, contending with the Nile River for that honor. More than from its mouth, upstream
Longest rivers of the United Kingdom Longest rivers of the United Kingdom This is a list of the longest rivers of the United Kingdom. There seems to be little consensus in published sources as to the lengths of rivers, nor much agreement as to what constitutes a river. Thus the River Ure and River Ouse can be counted as one river system or as two rivers. If it is counted as one, the River Aire/ River Ouse/Humber system would come fourth in the list, with a combined length of ; and the River Trent/Humber system would top the list with their combined length of . Also,