Very odd indeed! I wasn't sure what I was looking at there.
I have toyed with doing a really hard forum ride loop taking that in but it would be dependent on me being much fitter than I have been in recent years. I would have a lot of travelling to do to get there and back so I would probably aim to go up there for a long weekend. It would be a bit dodgy if the weather turned nasty on the day.
The descent off Great Dun Fell could be pretty scary if you didn't do a lot of braking! I have just done a short local descent at about half that gradient and was almost wiped out by a sheep that had been hiding behind a large rock...
We did Great Dun on a day trip to Sedburgh: up the Lune gorge, over to Knock, up and down Great Dun, Brough, Tan Hill, Kirkby Stephen and back to Sedburgh.
A magnificent if rather epic day out.
The descent from Great Dun is *very* fast if you want, and car free, but does feature a lot of sheep. It's the only UK descent I've ever done which is long and fast enough to feel the temperature rising as you come down.
I'd say it's the single toughest ascent I've ever done on a bike bar none: long, very steep and highly exposed to the wind. Awesome views across the lake district.