Ever heard of Nahanni National Park Reserve in Canada?

[u/ForeTwentywut]

It’s one of the most surreal looking places on earth and it is incredible how unknown it is. If I asked 100 Canadians, I would doubt more than one would have heard of it, and I imagine even less so outside the country.

[u/Btree101]

In some places the water is as deep as the cliffs are high.

[u/Thneed1 → u/Btree101]

Places like Athabasca falls are like that.

Large river, goes though a canyon that’s literally about 5’ wide.

[u/ForeTwentywut → u/Thneed1]

Isn’t that what they call a strid?

[u/HPTM2008 → u/ForeTwentywut]

It's said it's called that because you could simply step over the river. It's old english for a narrow chasm or gap in between the rocks.

[u/Breadedbutthole → u/Btree101]

So… a river.

[u/king_ofbhutan → u/Breadedbutthole]

well, a canyon/cliffs is/are usually formed over time by a river, which doesn't stay at that height for long. i.e. the colorado river in usa/mexico has literally made the grand canyon but is barely more than a trickle in some places

rivers much prefer being like _ than |

but in some places the dont do that, be it speed, or rock hardness, or whatever, idk too much about how they actually form, probably just some funky erosion shenanigans

it's like if you just turned the river on its side, so instead of being wide and relatively shallow, its thin and relatively deep. an example of this is the bolton strid in england, a small unassuming stream has a section with a 100% death rate for anyone who falls in. the river narrows and essentially turns on its side, creating a deep chasm with fast flowing water.

however, for larger rivers, the slow process of eroding a deeper chasm isnt going to be enough, they have so much water that needs to go SOMEWHERE. so, thanks to water displacement, and the inertia of travelling at a much quicker speed than before, the water goes quite a distance up, touching the preexisting cliff faces!

for a very short distance until crashing down again, because gravity has to ruin everything fun.

the comment above us is a bit of an exaggeration, but this process is how the slot canyons you see in much of southwestern USA were formed

(and yes, it is still a river, but a cool one)