Navigation apps are great, but for big picture inspiration there's still nothing like a printed sheet. Unfolded on your floor or pinned to a wall, a paper map can be way more than just a tool, becoming something of personal significance.

If you're a hill geek like us, you may have a particular favourite. Here's Ronald Turnbull on the "one Lakeland map that matters".

Harvey Superwalker - Lake District West

The world's best ever paper map? Difficult decision, this one. ChatGPT thinks it's the National Geographic's 'Torres del Paine National Park'. Excellent and inspiring choice –  or would be if that map actually existed.

But still, the soon-to-be-superhuman intelligence may be onto something here. The maps of the imagination being finer by far than anything printed on physical paper of the so-called Real World?

Let's not go there. Let's go instead to Lakeland, which is a place I prefer to Torres del Paine because of not having ever actually perambulated Patagonia. But even within that little Cumbrian corner, there's so much to take into account. Do I want an OS map with interesting paths marked on it that used to be there in the days of the deerstalkers, or do I want one that unenterprisingly only marks paths that exist on the fellsides of today? When I get onto some craggy ground such as Sca Fell, would I like to up the challenge even further by covering up all the contour lines with exciting little grey crag markings?

And that's before even considering the location. Do I desire a map with Great Gable and Haystacks and Yewbarrow and Coniston Old Man and the Crinkle Crags, or would it be nicer to not have any of those stony, uncomfortable summits? Would I wish to have on my one map the Harter Fell that's at the head of Kentmere, the one whose summit cairn is mostly made of old fence posts – or instead the Eskdale one, whose summit cairn is perched on a shark-shaped fin of bare rock? Do I need to include charming little Cat Bells – over-hyped, over-photographed Cat Bells with its slippery mudstone rock laid bare by the tread of many toes; or do I fancy a map that stops a sneaky 3km too far south, while still cleverly catching Castle Crag?

And how much do I mind if the map also takes in over-trodden, over-popular Scafell Pike? Because despite the orange peel and the huge cairn and the 47 other folk already standing on that cairn, it's actually not a bad hill at all, especially on the Eskdale side.

There is, of course, no such thing as a 'bad' hill. Any suggestion that Great Sca Fell, safely tucked away up on Superwalker Lake District North, is in any way less great than the just plain Sca Fell that forms such a fine midpoint of Superwalker Lake District West – well all that's just prejudice and personal preference. Fortunately, for those of us who perversely continue to prefer the 964m, crag-ringed, historically celebrated home of Central Buttress and the West Wall Traverse to a 651m hump of peat on the side of a slightly larger lump of peat, there's an objective way of reckoning this. So turn to the four billion year old truths of geology.

Lakeland is divided four ways, like a pie chart rather than a Venn diagram. North-south, the boundary is between the smooth, slippery mudstones that make up, among others, Cat Bells; and the rough, chunky volcanic rocks of what scramblers and climbers sometimes call the 'real' Lake District. East-west is more subtle. When my Dad told me as a wee lad (me, not my Dad), there's nothing worth bothering about east of Dunmail Raise, he was referring to the effects of the Ice Age. Because no matter how beautiful the bedrock, it needs a glacier to carve it into airy ridges and worthwhile climbing crags. Glaciers need ice and ice needs snow, and where the snow falls deep, like the rains of today, is along the western edge of everything.

All of which means that the best bedrock, carved into the most convincing mountain outlines, lies south of Cat Bells and west of Dunmail Raise. Exactly where Sue and Robin Harvey have placed the edges of the one Lakeland map that matters.