Although we all have an intuition of how large Earth is, sometimes a handful of factoids come along that knock our size conceptions of the planet sideways. For those of us unfamiliar with Earth’s river systems, this new video from YouTuber RealLifeLore may do exactly that. Because the world’s longest rivers are—long—and the biggest one, by square mileage, could even be its own continent.

RealLifeLore, a YouTuber who gives “answers to questions that you’ve never asked,” recently posted the above river comparison to his channel. The YouTuber has taken countless quantitative looks at esoteric topics before, much like this one. If you want to know just how huge the Pacific Ocean really is, for example, this channel is for you.

In this video the YouTuber tries to come up with a definitive answer for the question: Which of the world’s rivers is longest? A surprisingly difficult challenge as much of the geographical measurements of Earth are arbitrary. Especially in the context of comparison. The longest walkable distance on Earth, for example, is definitely up for debate.

A view of an incredibly long river flowing through a forested area as seen from space.

RealLifeLore

As for the top two contenders, they’re not surprising options. RealLifeLore notes that experts ultimately say that either the Nile River in Africa or the Amazon River in South America is the world’s longest. Although the details that underpin a final decision between the two make things a bit sticky.

RealLifeLore notes that rivers’ branching structures means it’s hard to find beginnings and endpoints for the flowing bodies of water. It’s also difficult to determine where exactly they finally feed into the ocean. On top of that, as the size measurement one uses grows smaller and smaller, the length of a river grows longer and longer; a phenomenon resultant from the fact that more minute measurements capture more of a river’s bends. (On a small enough measurement scale, a river’s length approaches infinity.)

RealLifeLore

As for the winner? RealLifeLore places the length crown on the head of the Amazon River. The YouTuber says that geographers peg the river at 6,992 kilometers, or about 4,344 miles, in length. Which makes it approximately 342 kilometers, or 212 miles, longer than the Nile. The Amazon isn’t just incredibly long either; apparently its total size is large enough to fit France inside of it eleven times over. The river—which is more of a massive branching system—is also responsible for 20% of the fresh water feeding into the ocean. Which is another factoid that recalibrates how important the Amazon is for Earth’s environment.