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How many of the world's longest rivers* have you even heard of? Here's where they are – and how best to see them.
10. Amur, China and Russia - 2824km
The tenth longest river in the world rises in the hills of western Manchuria, China, from the confluence of its two major affluents, the Shika and the Ergune and it flows east forming the border between China and Russia. The cities along the Amur offer a rare insight into the lives of inhabitants of border regions: orthodox churches stand a mere bridge away from the coiled incense sticks of Chinese temples.
A handful of local companies operate tours along the river and deep into the Russian countryside where some offer the option to dine with Ulchi communities.
Alternatively, you can go on a shorter cruise excursion on a break from the trans-Siberian train, which has options for all three regions covered by the Amur (trans-siberian.co.uk)
9. The Congo, Africa - 4700km
This river begins in the highlands of northeast Zambia, and continues in a counter-clockwise curve, meandering through the Republic of Congo, the Democratic Republic of Congo, the Central African Republic, Angola, Tanzania, Cameroon, Zambia, Burundi and Rwanda. See the Boyoma Falls in Kisangani, Congo (CDR) and the old port of Matadi, founded by Welsh journalist and explorer Sir Henry Morton Stanley in 1879. The river eventually feeds into the South Atlantic Ocean, to the North of Angola. It is best seen in combination with a stay in safari-style lodges and villas.
8. Paraná, South America - 4880 km
The eighth longest river in the world is formed by the confluence of the Paranaiba and Grande rivers in southern Brazil. The river forms a natural border between Paraguay and Brazil and Paraguay with Argentina. From the small town of Encarnacion, on the Paraguayan side of the river, you can see the bright-coloured wooden houses of Posadas, in Argentina, and from Pousadas, look back to Encarnacion, and marvel at the pristinely preserved ruins of the old Jewish settlement. Drive from Buenos Aires to the small river-port town of Tigre from where you can board a small vessel a full-day tour. Some will even take you to restaurants in hidden islands.
7. The Ob-Irtysh, Russia - 5414km
This river flows across western Siberia in a zigzagging diagonal from its source in the Altai Mountains to its end at Gulf of Ob (and thereafter into the Kara Sea - part of the Arctic Ocean north of Siberia). The first city on the river course is Barnaul, a hidden gem in Siberia from where you can explore the mountains a two-hour drive away. Also of note is Novosibirsk, Russia's third largest city and a great showroom for industrial soviet architecture.
River cruise options are hard to come by for this region. However, Into Russia, which specialises in the region, offers itineraries incorporating the city of Omsk on the banks of the Ob.
6. Yellow River, China - 5464 km
With its source in the Bayan Mountains, a south-central range in the northern province of Qinghai in China, the Yellow River flows through nine Chinese provinces. These regions were among China's most prosperous and the Chinese regard the Yellow River as the cradle of the nation.
Nature and wildlife enthusiasts and those in search of culture will find plenty to enjoy. Cities along the route include Lanzhou, Zhongwei, Yinchuan, Baotou, Yan'an, Luoyang, Zhengzhou, and Kaifeng. The ancient cities of Yinchuan and Kaifeng are previous capitals and both bear their dynastic imprints. Local boat companies operate from most of these cities and are preferable to the larger cruises which focus mostly on the Yangtze.
5. Yenisei River, Mongolia and Russia - 5539 km
The Yenisei flows from Mongolia northerly to the Yenisei Gulf and finally into the Arctic Ocean. Most of its course is through the white, paralysing landscapes of a Russian Winter but in Krasnoyarsk you might be able to enjoy something of a Mediterranean Summer –- temperatures in this Siberian enclave often reach 30 Celsius or above in summer – only to drop to minus 30 Celsius in winter. Stop in Divnogorsk for a traditional dip in the Yenisei frozen waters. This river is the largest course of water to meet the Arctic Ocean. Short trips and day cruises are available on local passenger vessels - should you happen to drop by.
4. The Mississippi, US - 3766 km
North America's longest river touches an impressive number of states: with a distant tributary in Montana, it rises in northern Minnesota, then flows through through Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi state and Louisiana, threading through some of the most dramatic scenery in the US.
With visits to antebellum plantations, historic battlefields, quaint southern towns and iconic cities like Baton Rouge the route between New Orleans and Memphis offers plenty in the way of history and regional culture and flavour.
3. Yangtze, China - 6418 km
"If you haven't been up the Yangtze, then you haven't been anywhere", goes an old Chinese saying. The longest river in Asia rises from the glaciers of the Qinghai-Tibet Plateau eastwards across southwest, central and eastern China before emptying into the East China Sea north of Shanghai.
It touches 10 Chinese provinces and, if these days the riches of the Yangtze come mostly from its mammoth hydroelectric potential, it has served China for much longer as a source of food and water for the irrigation of its rice fields. One of the most impressive sights along the river is the Three Gorges Dam, the world's largest power station. More bucolic sights to be enjoyed from the ship include Nanjing's Purple Mountain.
2. Amazon, South America - 6516 km
Rising in the Peruvian Andres, the Amazon is the largest river in the world by volume: with a discharge of around 209,000 cubic metres per second, it holds one fifth of the world's fresh water supply.
Its most celebrated stretch goes deep into the Amazon rainforest where dense and tropical flora are the main attraction. The most immersive tours will also take you to see villages lost in time and the colourful fauna and some of South America's best preserved colonial heritage.
1. The Nile, Africa - 6695km
Coursing through a dozen countries the Nile is the world's longest river. From the windows of your ship you'll see landscapes unchanged since Cleopatra walked these banks. The most important monuments are all located close to the Nile as it is, and has been for millennia, the country's primary water source. Most Nile cruises sail between Aswan and Luxor, stopping off to see the temples at Kom Ombo, Edfu, and Esna – a 200-km journey full of archaeological riches.
Although visitor numbers have been affected by recent unrest, there are still plenty of option.
*Length is defined as the distance between the furthest tributary and the mouth of the river
Explore these amazing rivers in the photo gallery above.
The Telegraph, London