60 free Amazon River trivia questions with answers — geography quiz, new questions added Aug 2026.
The Amazon is the biggest river on Earth by any measure that matters: it pours out more water than the next seven rivers combined, drains a basin the size of Australia, and pushes fresh water so far into the Atlantic that ships have drunk from the sea out of sight of land. This quiz starts with the basics (which ocean, which country, which city) and works up to the argument over its true source, the 2014 kayak survey that lengthened it by 80 km, the never-settled contest with the Nile, and the odd fact that no bridge crosses it anywhere. It also covers the geology (the river used to flow west into the Pacific until the Andes rose), the history (Pinzón's 'sweet sea', Orellana's women warriors, the rubber boom that built an opera house in the jungle, the Trans-Amazonian Highway) and the wildlife: pink botos, giant otters, anacondas, arapaima, candirú, electric eels and the bull sharks found 4,000 km upstream. It finishes with the tidal bore surfers ride, the underground Hamza 'river' and Martin Strel's 66-day swim. Every answer was checked against Wikipedia's article on the Amazon River and related pages, and each question shows the sentence that supports it. Try our Brazil, rainforest and rivers quizzes next.
30 of 60 questions with answers and explanations. Play the quiz
Q 01The Amazon is the largest river in the world by which measure?
Discharge volume
Its length is disputed with the Nile, but nothing comes close to its flow of over 200,000 cubic metres per second.
Q 02Into which ocean does the Amazon empty?
Atlantic
For millions of years it flowed the other way, toward the Pacific, until the Andes rose and blocked it.
Q 03Which is the largest city on the Amazon?
Manaus
With about 1.9 million people it holds roughly half the population of the Brazilian state of Amazonas.
Q 04After meeting, the Rio Negro and Solimões flow side by side without mixing for over how far?
6 km
Brazilians call the junction the Meeting of Waters, and it is where the river officially becomes the Amazon in Brazilian usage.
Q 05The Amazon's discharge is greater than that of how many of the next-largest independent rivers combined?
Seven
It accounts for about 20% of all river water entering the world's oceans.
Q 06Roughly what share of the world's river water flowing into the oceans comes from the Amazon?
20%
Two of the ten biggest rivers on Earth by discharge are themselves tributaries of the Amazon.
Q 07The Amazon basin covers roughly what fraction of South America?
About 40%
At around 7 million square kilometres it is the largest drainage basin on the planet.
Q 08A 2014 study placed the Amazon's most distant source in which river's drainage?
Mantaro
For nearly a century the honour belonged to the Apurímac on Nevado Mismi; James Contos measured the rivals by kayak.
Q 09Most geographers place the start of the Amazon proper at the confluence of the Ucayali and which river?
Marañón
The junction lies upstream of Iquitos, Peru; Brazilians call the stretch below it the Solimões.
Q 10The Amazon enters Brazil carrying what fraction of the flow it finally discharges into the sea?
One-fifth
Even at that point it already carries more water than any other river on Earth.
Q 11The Amazon has how many tributaries in total?
Over 1,100
Twelve of them are more than 1,500 km long in their own right.
Q 12Which Spanish explorer in 1500 became the first documented European to sail up the Amazon?
Vicente Yáñez Pinzón
He called it Mar Dulce, the sweet sea, because its fresh water pushed so far out into the ocean.
Q 13The Amazon reportedly got its name after Orellana's expedition was attacked by warriors led by whom?
Women
They reminded him of the Amazon warriors of Greek mythology.
Orellana was second-in-command on a 1541 expedition seeking El Dorado and what else?
Q 21How many bridges span the full width of the Amazon River?
None
It is not too wide to bridge; the river simply runs through rainforest with few roads or cities, so ferries do the job.
Q 22Why does the Amazon not form a significant delta?
Waves and tides carry the sediment away
The world's great deltas all lie in sheltered water, whereas the Amazon empties straight into the open ocean.
Q 23The Amazon's freshwater plume alters the colour and salinity of the ocean over an area of up to how much?
2.5 million sq km
A valley of cinnamon
True cinnamon is not native to South America; Pizarro probably found related laurel-family trees.
Q 15Orellana's party reached the mouth of the Amazon on 24 August of which year?
1542
The trip proved the great river was navigable end to end.
Q 16Which Portuguese explorer was the first European to travel up the entire river, reaching Quito in 1637?
Pedro Teixeira
He returned by the same route; a decade later Raposo Tavares trekked over 10,000 km from São Paulo to the river's mouth.
Q 17Archaeologists estimate how many indigenous people lived around the Amazon when Orellana travelled it?
More than 3 million
Repeated burning created fertile terra preta, the 'Indian black earth', that supported large chiefdoms.
Q 18What is 'terra preta de índio'?
Fertile dark soil made by ancient burning
The practice may date back 11,000 years and let large settlements farm the poor rainforest soils.
Q 19Marajó, at the Amazon's mouth, is the world's largest example of what?
Combined river-sea island
Its pre-Columbian Marajoara culture may have supported 100,000 people.
Q 20Including the Pará river and Marajó's ocean frontage, how wide is the Amazon estuary?
About 325 km
The main channel alone is only about 15 km across between the islands of Curuá and Jurupari.
For centuries ships have found fresh water at the surface while still out of sight of land.
Q 24What is the pororoca?
A tidal bore that surges up the river
Its leading wave can be 7.6 metres high and travel 800 km inland.
Q 25What is the name of the natural channel that links the Amazon and Orinoco basins?
Casiquiare
It is the largest river on Earth joining two major river systems, a phenomenon called bifurcation.
Q 26The forests flooded each year when the Amazon rises over 9 m are called what?
Várzea
The flooded area swells from about 110,000 sq km in the dry season to 350,000 in the wet.
Q 27Large ocean steamers can navigate the Amazon as far as which city, 1,500 km from the sea?
Manaus
Smaller ocean vessels can go on to Iquitos in Peru, 3,600 km from the Atlantic.
Q 28What was the Hamza River, announced in August 2011?
A large aquifer running beneath the Amazon
The underground flow parallels the surface river.
Q 29Before the Andes rose, the proto-Amazon flowed west as part of a river system shared with which African river?
Congo
The continents were joined as western Gondwana until about 80 million years ago.
Q 30Roughly how many species of fish were known from the Amazon as of 2011?
More than 5,600
Around fifty new species are described every year, and the basin holds over 1,200 kinds of catfish alone.