See title.
Don't know if this has been discussed before, but I recently saw a video from 2016 about a stretch of river in England with an alleged 100% death rate to those who jump in it. Apparently the "Strid" looks innocuous but is surprisingly deep and the current strong enough to trap you underwater. I looked for more information about it, and all I can find seem to be based on this video. There aren't any official sources confirming the lethality of the place although there are signs posted along the path next to the river. Also I don't believe in the claim that no one was ever able to measure its depth because any equipment gets washed away. There are for more inaccessible places around the world where scientists take all sorts of measurements, so I don't understand why there isn't more complete information on this particular river. Maybe it's all just an urban legend and although dangerous the Strid isn't nearly as deadly or mysterious as people hype it to be.
Anyway, share some outdoor places you know that look normal and easy to access but are dangerous.