People who have been to Geneva surely have admired the view of Mont Blanc. On clear days it is possible to see the mountain which is 70 km away and more than 4000 m higher than the city. (To be honest, I don't know whether one can actually see the peak but it's not too relevant.)
This motivates the question: What's the biggest altitude difference between two points on earth which are visible from each other and where are they?
I'd prefer if the two places are actually really visible from each other, so please at least indicate in your answers if
- one of the places is covered in smog or clouds most of the year or
- one point only appears as a small glimmer on the horizon from the other.
Of course there's no clear line between passing and not passing these criteria, but I hope that's okay. I tried to find an answer on the internet and this site but without any success. Maybe I used the wrong keywords.