In reply to Fex Wazner: By the ecologist's definition, there is no significant 'Wilderness' left in western Europe. But then, how much is there anywhere else? I'd have thought that most wild areas in North America have some marks of human presence, if only tracks and cabins; tribes live and farm in the most remote parts of Amazonia; people have lived in the Himalaya for thousands of years; our species probably came from the African savannah (and where is more of a 'wilderness' than an African game park full of lions and elephants?)...deserts and ice caps would seem the to be the places with the fewest traces of human activity...and even these are being altered by human-driven climate change. In the end, we are as I think Norrie intimated, as much a product of nature as any other organism...such observations tend to undermine the rigorous scientific definition of wilderness somewhat.
In the case of the UK, either the term Wilderness is unhelpful, or we need a looser definition, perhaps based on subjective experience. We're not likely to stop using the word, so I suggest that in everyday non-ecologist speak we could usefully redefine it. Or perhaps just go with the non-technical definition offered by the Oxford English Dictionary: 'a region or area that is uncultivated and uninhabited by human beings' and/or 'an empty or pathless area or region'. On these criteria there are many small patches of wilderness in the UK, even south of the border. Notice there is no reliance on tense in the dictionary definition. Wilderness IS uncultivated and uninhabited, but there is no reference to it's having HAD to be so in the past. So depopulated deforested areas of the Highlands, in which thriving crofting communities once lived, would qualify as wildernesses. Ecologists would grumble, but there you go, it's in the dictionary so it must be true.
I'm not bothered by the technical definition (eg lack of all human traces both past and present, altogether), but for me at least, as someone who goes into the mountains a lot, the term wilderness still means a little more than the dictionary definition. I'd call a place a wilderness not because of any easily measured criteria, but because of the sort of experience I could have there. Characteristics of an experience of UK wilderness might include: solitude, a measure of self sufficiency, a feeling of at-one-ness with nature, no signs of modern industrialised society impinging on my consciousness to remind me of the often squalid world we've created (so, I'd have to be out of sight and hearing from roads, I'd have to not be able to see windfarms, dams, pylons, antennae, city lights... and perhaps if I was nitpicking I'd have to wait for a quiet moment when there were no aeroplanes flying overhead), no permanently occupied houses in sight: If enough of these conditions applied in a particular area, and if it was big enough to go out into and keep having the same sort of experiences in for a day or two's walking, then I'd happily call the area a wilderness. Nebulous and subjective I know, but I don't think I'm alone in using the word in this way.
Off the top of my head, UK areas of significant extent in which I could have a wilderness experience include:
The Cairngorms, Monadhliath (for now, until it's covered in windmills), Ardverickie Forest / Ben Alder, Black Mount / Glen Etive hills, Jura, Ardgour, Knoydart, Mullardoch/Monar hills (if I was to confine myself to the heads of the lochs and forget about the dams), Coulin Forest, Torridon / Shieldaig Forest, Letterewe / Fisherfield Forest, Seana Braigh area, Assynt, South and North Harris hills, Pairc, the bogs of northern Lewis (until they're covered in windmills), Rum, the west coast of Hoy perhaps, a quiet day somewhere obscure in the Southern Uplands, the North Pennines, at a push the back of Skiddaw, Carneddau in winter, perhaps quieter bits of the Berwyns (?), Rhinogs (if I couldn't see Trawsfynydd powerstation), Dartmoor in the fog, the middle of the Mournes (I'd say the big stone wall had aged into the landscape enough not to impinge significantly).
Of course, my wilderness experience would be shattered or at least severely cracked if I could see even a very distant windmill from the top of my hill. Hence I'm dead against poorly planned windfarms.