Walkers challenged to deep clean the Three Peaks
Organisers hope about 100 volunteers will join in a coordinated litter pick on the highest mountains in Scotland, England and Wales.
"Banana skins. Plastic bottles. Banana skins. Tissues. Banana skins. Orange peel," says Rich Pyne.
As we set off from the car park at the Glen Nevis visitors' centre, Rich was pretty clear about what he expected to find.
He came up with the idea of a litter pick across Ben Nevis, Scafell Pike and Snowdon - due to take place on Saturday 12 October - after watching people on a guided walk eating their lunch.
"I was just appalled by the amount of rubbish that was flying around on the summit," he says.
"So while my clients were eating, I collected two or three kilos of rubbish, debris. That took a couple of minutes.
"I made a bit of noise on Facebook and it developed from there over a couple of days."
Bag of food
One of the people already signed up to take part on what they are calling The Real 3 Peaks Challenge is Callum Macrae, who joins Rich and me for a morning on Ben Nevis.
He says he would expect the early stretches of the mountain to be relatively litter free.
"Nobody's really got round to eating all their food, to drop it out", he explains.
Just at that moment we walk up to a leopard print plastic carrier bag, dumped at the side of the path.
Inside it, predictably enough, a couple of slimy brown banana skins. Some sandwiches, still in their plastic packaging. A multi-pack of chocolate bars. And a bottle of drink.
Perhaps whoever left it there had genuinely meant to collect it on their way down from the summit.
Or perhaps they thought they were doing those who would come after them a favour, leaving some free food to be foraged.
But Callum is more cynical.
"They probably thought 'Oh I'll just drop it', then one of us fools will come and pick it up," he says.
By now we are an hour into our walk and I decided to talk to some of the people on the Ben, to find out what supplies they are carrying with them and what their plans are for dealing with the waste.
Alex, Dale and Rob from Northamptonshire are on a once-in-a-lifetime expedition up the UK's highest peak. They are carrying whisky in a hip flask, "quite a lot of water", and some chicken sandwiches.
Two people from Paris are on holiday and aiming for the summit "if we can manage". They have lunch and some water in their back-packs.
And Kinlay and Andy, from Portishead in North Somerset, are carrying cereal bars, crisps, drinks "and some chocolate, obviously" to fortify themselves for their walk.
All of them insist they plan to carry their litter back down with them.
They had carried the packs up full, so why would they not take them down empty?
And who would possibly want to mess up such a wild and beautiful place?
But you only have to look at the path to see that not everyone does what they say.
We find chocolate wrappers, some drink cans, a lot of the tiny blue or red plastic tabs you get when you open certain brands of bottled water and banana skins, of course.
We also come across two plastic soles which seem to have fallen off disintegrating trainers and, bizarrely, a dog bowl that had been carefully placed alongside a fast flowing burn.
Someone jokes: "Perhaps the dog would only drink Highland Spring (mineral water), and refused to drink from an actual highland spring".
Callum Macrae is not surprised.
"No-one will ever admit 'I drop litter'," he says.
"They might be on the top, and something will fall out (of their bags or pockets) by accident, and they might not pick it up again.
"It's a shame, really."
The three peaks event is designed to complement clean-ups that are organised on each of the mountains.
Volunteers from the Snowdonia Society, for example, clean the highest peak in Wales.
The Lake District National Park authority has in the past lent equipment to groups gathering waste from Scafell Pike.
And the John Muir Trust runs regular litter picks on Ben Nevis.
'Big floaty dress'
But Callum and Rich are confident there will be enough waste left to make one final effort worthwhile.
"It's a continuous thing," Callum says.
"As long as there's people, as long as there's a footpath up the hill, then there will be people that go up it and drop litter."
And Rich Pyne says you can never tell exactly what you will find.
He says: "The most unusual one was a dress, would you believe, on the summit.
"It was tucked in a corner of the Observatory. A big, floaty dress. Size 18 to 20."
It was found earlier this summer. But no-one knows how, or why, it was on the Ben.
"I don't see anybody back-packing with one of them", he laughs.
Get more information on the Ben Nevis clean-up: email@example.com
Contact organisers of the Scafell Pike event: firstname.lastname@example.org
Details on what's planned in Wales: email@example.com