The Most Dangerous Stretch of Water in the World: The Strid at Bolton Abbey, Yorkshire
I know, I know, it's a clickbait title^. But I stand by it, because the water is so deceptive, and so pretty, and there's a path that leads straight down to it and that jump looks very, very possible...
The 12th century legend is the "Boy of Egremont", immortalised in poetry by the famous William Wordsworth. His "The Force of Prayer" is about the Strid and the Boy of Egremont, and the full text is here: http://www.bartleby.com/145/ww342.html
Also, I need to make one correction: I say "a hundred metres upstream", but that shot's actually about that far downstream. I couldn't fix that in post, but since the river's basically the same for a mile or so in each direction with no significant confluences, it's a small enough slip that I don't think it's too bad. The amount of water is the same! -yt