Somewhere out west of Whiterun, IIRC, there is an old Nordic ruin off the side of the road a bit. It's not marked on any of the maps and doesn't show up in the game map even after you've found it.

There is a circle of standing stones and activation pedestals at the base of these stones. There are figure plates at the base of two of the standing stones and on the third (the most westerly) the figure plate is still mounted at the top of the stone. Off to the side is a grated pit with a treasure chest inside.

I have tried to figure out the combination to open the grate. But turning the pedestals such that they correspond to the figures on or at the base of each stone/pillar doesn't do it.

Any ideas how to get to the chest?

Keep playing with them, try all combinations, you'll get it eventually, I can't remember the right one myself but I remember it took me a minute of attempts to get it right.

There's a small white triangle at the foot of the pedestals. You need to rotate the pedestals so the triangle points at the correct figure. I think the figure plate closest to a certain pedestal shows which figure needs to be shown on that pedestal.

I understand that, and that's what I did. No joy.