Barring Florida- I reckon you can make a mountain out of a molehill. Plenty of local hills but the highest is only 850 ft above sea level and you start near sea level. BUT make that 850ft offroad and a mile long at 12 to15% with ruts- loose gravel- flints and slippery green chalk and I would rather climb Ventoux occasionally. And on the road we have a couple of baskets at 1 mile at 12% with a little section at 20-or the real basket of a 16% that I do only make certain I have the right gearing and I am fit.

Yep- I have climbed one of the famous Mountains that is recognised to be hard. Took me a long time though at an average of 5mph. I got there and without too much pain. In fact at one point I thought I was going downhill but that was because the slope had lessened to 5%

First mile of the climb and I had a problem but then got into a rhythm. Once that rhythm came I had the right balance between Cadence and speed---Or legs and lungs- Or effort- and That rhythm stayed with me to the top. OK- Steepest was at around 12% but 13 miles at 7.5% average takes it out of you. Or would do if I hadn't found that rhythm.