A path - above or below lawn level?

I will try and find a photo of this later, but in the meantime I am looking for opinions please.

My grass (cannot currently call it a lawn, as that would be plain cheeky) has a path up the middle which consists of slabs laid end to end. The existing path looks like it was laid in the dark ages, is somewhat 'coggly' and is being overtaken by the grass. Its also not straight (or at least it looks skewed when looking at it from the kitchen window).

So, I am considering lifting it and relaying it - possibly with the existing slabs, or maybe with new ones (I quite like York stone), and then to have it with a gravel border (slate?) maybe four inches at either side, all held in with boards to separate it from the grass.

Question is, do I have the path raised above the grass level (so I would have to strim the lawn edges against the board when cutting the grass), or do I have the path below the grass level so the top of the boards are level or just under level of the grass?

 

Good morning "M" I old enough to be called experienced and I say your sound advice is spot on

 

If I was to keep them at lawn level, without boards and gravel, how best to make sure they stay level, straight and without stray grass in the gaps?