Stac Pollaidh is one of the best known and most popular mountains in Scotland, its steep pinnacled ridge often likened to a porcupine. The true summit is at the west end; although most of the difficulties on the ridge can be avoided, there is a final sting in the tail in the shape of a very short but difficult and exposed scramble up the final tower. This has to be reversed on the descent, making the actual summit perhaps the most technically difficult to reach on the British mainland. It is harder than the summit block of The Cobbler, and many non-baggers will give it a miss.

https://www.walkhighlands.co.uk/fionas/stac-pollaidh

Feels otherworldly to me

Of course it's Scotland :) I so want to go hiking there!