15 Facts About the Amazon River That’ll Blow Your Mind

The world’s mightiest river, an unrivalled wildlife-watching destination and still one of the least explored regions on earth – find out more about this fascinating place with these interesting facts about the Amazon River.

It nurtures the largest rainforest on earth and provides life for a mind-boggling array of flora and fauna – the Amazon River is one of South America’s most fascinating destinations to discover and, despite centuries of in-depth exploration, it’s still a mystical place that hides innumerable secrets. Learn all there is to know about this incredible ecosystem and make your Amazon River visit in South America all the more rewarding.

Sunset over the Amazon River.
Sunset over the Amazon River. Photo: Shutterstock

Here are 15 amazing facts about the Amazon River that are sure to blow you away:

1. The Amazon River originates in Peru

Believe it or not, there’s been wide speculation over the real ‘source’ of the Amazon River for decades with researchers at constant odds over findings. The most widely believed theory is that the Amazon River flow originates in the high Andean mountains of Peru, namely the three rivers of Mantaro (the furthest upstream source), Apurimac (the most distant uninterrupted source) and Maranon (the main source by volume).

The Maranon River flows upstream of Iquitos, Peru’s Amazon adventure capital and one of the most spellbinding places to enjoy Amazon River adventures.

Maranon River, Peru
Maranon River, Peru. Photo: Shutterstock

2. The Amazon River System meanders through nine South America countries

After starting its seemingly slow and subtle voyage in the highlands of Peru, the Amazon River traverses through Ecuador, Colombia and Venezuela before entering Brazil and flowing out of its Atlantic coast. However, its tributaries also flood the Amazon basin in Bolivia in the south, home to the Madidi National Park (one of the Amazon’s largest protected reserves) as well as Suriname, Guyana, and French Guiana.

Given each country’s distinctive tourist infrastructure, some spots are simply better and more rewarding to visit than others, depending on whether you’re after a land-based Amazon tour or Amazon River cruise. The most established visiting hot-spots are in Peru (Iquitos and Puerto Maldonado), Ecuador (Coca), Brazil (Manaus) and Bolivia (Rurrenabaque).

River map, photo credit; Chimu Adventures
Amazon River map. Photo: Chimu Adventures

3. A Slovenian athlete once swam almost the entire length of the Amazon River in 66 days

Defying the odds of dangers in the remotest regions of the Amazon River basin, Martin Strel took home his fourth Guinness World Record for long-distance swimming when he took on the mighty Amazon River in 2007. Already a veteran of the sport, which saw him complete swims along the Danube, the Mississippi, the Parana and the Yangtze rivers, Strel swam a total of 5,268km (of the Amazon’s entire 6,400km-length), a distance which is actually greater than the width of the Atlantic Ocean.

His tactic for dodging flesh-eating piranhas? Have support boats flanking him, ready to drop raw meat and blood into the river to distract any hungry critters. For quite obvious reasons, Strel’s nickname is ‘The Hero in a Speedo!’

Martin Strel, Guinness World Record holder, photo credit; Amazon Swim
Martin Strel, Guinness World Record holder. Photo: Amazon Swim

4. The Amazon River provides 20% of the ocean’s fresh-water supply

It’s an astonishing percentage when one thinks about it: one-fifth of the fresh water that flows into our earth’s seas flow into the Atlantic at the Amazon River Delta in northern Brazil. This is the largest river delta on our planet (discharging more freshwater than the following seven largest rivers combined) creating a muddy patch of salty-vs-fresh water that covers an area of 2.5 million sq km!

Largest freshwater river, photo credit; Shutterstock
Largest freshwater river. Photo: Shutterstock

5. Researchers discovered an entire coral reef system at the Amazon River Delta in 2016

It is at the very confluence between river and ocean that scientists discovered an enormous coral reef a couple of years ago, one that stretches for more than 1,000km and covers an area of over 9,500 square kilometres. Hidden from plain view for decades due to the massive sediment upheaval caused by the river’s flow, the reef is believed to be home to a unique ecosystem comprising a wealth of marine life.

Hints of the reef’s existence were first noted back in the 1950s although the find was only confirmed in 2016 and the first photos not released until 2017. Over the last couple of years, researchers have discovered giant sea sponges ‘as heavy as a small elephant’ and an impressive collection of exotic fish, sea stars, sponges and coral. Greenpeace, who was responsible for the first documented research of the reef, immediately set up a campaign to protect this incredible new natural discovery from the looming threat of oil-drilling.

River delta of the Amazon, the largest river in the world, seen from space, photo credit; shutterstock
River delta of the Amazon, the largest river in the world, seen from space. Photo: Shutterstock

6. The Amazon River used to flow backwards

The creation of the Andes Mountains some 15 million years ago can be regarded as the most defining moment in the evolution of the Amazon River. Up until the rise of this incredible mountainous border, the river flowed out into the Pacific Coast of South America. Remaining landlocked for nearly five million years, the relentless river finally found its ocean outlet once again, only this time, in the opposite direction – straight into the Atlantic.

7. The Amazon River and Rainforest host a jaw-dropping array of unique wildlife

The Amazon Rainforest famously hosts between 10%-30% of the flora and fauna species on earth (and that’s just the ones we know about) representing one of the most biodiverse regions on our planet. The Amazon River itself and all its countless tributaries comprise an ecosystem all their own, home to more than 2,000 species of fish and more than 400 amphibians. The rivers in the Amazon are the basis of all life so Amazon small-ship cruises are especially rewarding for spotting wildlife on the river shores.

The most famous creatures that inhabit this region include sloths, anacondas, piranhas, river dolphins, innumerable birds including macaws and toucans and a crazy number of frogs, spiders, snakes and other insects. One of the rarest and most endangered Amazon River animals is the boto, a dolphin whose skin is so thin it can appear grey or pink (hence its nickname – pink river dolphin) depending on how excited it gets and how much its blood-vessels expand.

The dense jungle canopy of the Amazon Rainforest may well host a stunning amount of wildlife yet spotting them in huge numbers is an infamous challenge. Check out the glorious wetlands of the Pantanal for more Amazon animals and arguably some of the most rewarding wildlife encounters of all. We compared the two stellar and distinct destinations, right here.

Pink Dolphin swimming in the water of the Amazon river and looking up
The boto ‘pink river dolphin’ of the Amazon. Photo: Shutterstock.

8. There are no bridges built across the Amazon River

Bar a few unique towns that have been built on the shores of the Amazon River, there are surprisingly few settlements along this very long river’s edge, which means no permanent bridge has ever been built. The lack of major infrastructure is what lends Amazon river tours their distinctly ‘remote and isolated’ feel. To really get anywhere, you must hop aboard a boat at some point: this is the only way to travel further along the river and to reach some of the more remote eco-camps.

Reflected jungle in the Limoncocha lagoon in the Ecuadorian Amazon
Reflected jungle in the Limoncocha lagoon in the Ecuadorian Amazon, photo credit; Shutterstock

9. The Amazon River has a hidden twin-river flowing below it

The Amazon River made headline news back in 2011 when scientists finally confirmed the existence of an ‘underground Amazon River’, which mirrors its above-ground twin in length and flow. The Hamza River (named after the scientist leading the research group) flows some 4km underground and although it’s believed to be up to four times wider than the Amazon River itself, it boasts only 1/34th of its water volume.

Underground Amazon RIver, photo credit; Valiya Hamza
Underground Amazon RIver. Photo: Valiya Hamza

10. The River boasts an impressive seasonal fluctuation of up to 15m

The Amazon is the greatest flowing river on earth, discharging a breathtaking 200,000 cubic metres of water into the Atlantic every single second. Yet what is even more impressive is learning about the seasonal water-level rises and the consequential ‘flooded forests’ that are created along the river’s sides. These varzeas, as they are known, facilitate longer and deeper Amazon River cruising, allowing for greater explorations of remote regions one wouldn’t normally reach during drier months of the year.

The Amazon’s flow has been the subject of intense studies for more than a century with a greater emphasis placed in the Amazon Basin, where fluctuations are at their most extremes. Manaus, in Brazil, normally records the highest water-level rises each year of between 10 and 15m. Seasonal changes are dictated by rainfall, of course, with the highest river levels usually recorded between December and May and lower levels (fantastic for lodge-based Amazon tours which include more hikes through the rainforest) between June and September. Read more about the Best Time to Visit the Amazon before planning your trip.

sailing a boat through a flooded forest in Latin America
Sailing a boat through a flooded forest in Latin America. Photo: Shutterstock

11. The Amazon Rainforest & River rely on the Sahara Desert for their very existence

We all know that we live on a planet whose incredible ecosystems are linked in more ways than we could ever understand yet, in the Amazon, the proof is in the nutrients. Both the rainforest and river of the Amazon are fed pivotal minerals (like phosphorus) from sands which blow across the Atlantic all the way from Africa’s Sahara Desert.

It’s been tens of millions of years since Africa and South America were joined, and it’s astonishing to know the two continents are still so intrinsically linked. Check out this incredible 3D video created by NASA using satellite info on the Sahara sand’s long journey across the seas.

12. The apex predator in the Amazon River, the black caiman, is also one of the most endangered wildlife of all

Long hunted for its valuable skin, the Amazon River’s black caiman is something of a legend. The most feared predator in the entire rainforest, the black caiman is one of the largest members of his species, anywhere on earth. Unlike the ‘run of the mill’ Amazon caiman, which is relatively small and weighs up to about 40kg, the black caiman can weigh 25 times as much and grow to an average of 5m in length.

The bad news is that this fearsome creature is highly endangered and the good news is that your chances of running into one, accidentally, are quite low.

Keep all hands and feet in the boat, kids!

Amazon River Caiman, photo credit; Shutterstock
Amazon River Caiman. Photo: Shutterstock

13. Biologists studying the region have a wicked sense of humour

Scientists are indeed renowned for their quirky sense of humour, and it seems most of them work in the Amazon. Some of the most unusual animals to see in the Amazon include the Jesus Christ Lizard (yes, it walks on water), the Prince Charles Stream Tree Frog in Ecuador (apparently named after the Prince’s rainforest conservation efforts), the Vampire Fish (those fangs are real!) and the Peanut Head Bug. Read more about the Top 10 Animals to Spot in the Amazon.

14. Thrill-seeking daredevils surf the Amazon at select times of year

Pororoca is the name given to a spectacular tidal-wave phenomenon (tidal bore) that occurs in the Amazon River delta during select full moons about 2-3 times a year. In these unique circumstances, the ocean tide manages to beat the Amazon River flow, causing colossal (and backwards) tidal waves that can travel up to 800km inland. An annual surfing championship has been running here for the last 20 years.

15. The Amazon River and its entire ecosystem are facing their biggest threat yet

The Amazon is facing its biggest fight to date. The Brazilian president seems to be intent on relaxing protection laws for the Amazon Rainforest, appearing to favour agricultural interests over those of indigenous Amazon reserves. The indigenous inhabitants of the region have historically been its most fervent protectors: given that they rely on the river and forest to survive, they are the most ardent protesters against deforestation, mining and oil drilling.

The Amazon is the largest remaining rainforest we’ve yet to completely ruin on our planet. Although it may seem ‘too big a fight’ to take on, individually, there are many personal and straightforward steps we can all take to help curb the impact on this incredibly precious natural asset. They include:

  • Reducing your meat consumption (Latin America is one of the largest exporters of beef on the planet, and pivotal rainforest land is being bulldozed for farming)
  • Reducing your use of paper and wood (purchase products with the highest rate of recyclable materials)
  • Do some research before buying ‘big-brand’ items (many mega-corporations invest in toxic oil pipelines in pristine Amazon wilderness)
  • Support Rainforest Action Groups (environmental action groups can be highly effective in forcing change – in the 1980s, ecological activists convinced Burger King (US) to stop buying beef from the Amazon regions of South America in one of the most successful campaigns ever held).

Want to experience one of our planet’s most astonishing destinations? Then join us on an Amazon cruise and explore some of the most inaccessible corners of this glorious natural wonder. Swim with dolphins, dodge black caimans, and be awe-struck by the inherent beauty of the magical Amazon River.

We offer Signature South America itineraries onboard luxurious riverboats and include overnight stays in charming eco-lodges built along the shores of the Amazon River in Brazil, Peru, Bolivia, and Ecuador. Don’t wait any longer and go on a South America Adventure!

Author: Laura Pattara

“Laura Pattara is a modern nomad who’s been vagabonding around the world, non-stop, for the past 15 years. She’s tour-guided overland trips through South America and Africa, travelled independently through the Middle East and has completed a 6-year motorbike trip from Europe to Australia. What ticks her fancy most? Animal encounters in remote wilderness, authentic experiences off the beaten trail and spectacular Autumn colours in Patagonia.”