Downstream from Hafragilsfoss
… and I get why, because this bit of the Jökullsá á Fjöllum (“glacial river in the mountains”) is really quite lovely. Nice walls with cool geology layers, twists and turns, a black sandbank, the works. 10/10 would hike here again.
The river, born in the massive Vatnajökull glacier far to the south, has about 100km to go before reaching the north coast.