I have a nice black and white poster of Mount Everest on the wall at the top of the stairs in my house. I got it at Stanfords, the map shop in Covent Garden. I probably would have bought it even before I saw who had taken the photo. The mountain is haughty and proud, an enormous glacier fills the valley in front and in the foreground – giving scale to the scene and a sense of infeasibility to the task facing the men inside them – is a little collection of tents. "Camp at 20,000 feet with Everest in the distance. Photograph: AFR Wollaston, 1921" reads the caption. The picture was taken by my grandfather.

Grandfather? 1921? Yes, I know, we procreate late in my family. He was born in 1875, I know people whose granddads were born in 1975. I never knew him of course – he died 31 years before I was born. Actually he was murdered, but that's another story. The point is, he was the doctor and the naturalist on the first Everest expedition, in 1921. They weren't seriously expecting to climb it; it was merely reconnaissance.

Things were different back then. The chaps who came to this part of the world all knew each other from Winchester or Cambridge or wherever, they could afford to take several months off from their jobs if they had them, and they came inappropriately dressed in wool and tweed and most probably had some inappropriate attitudes towards the locals who carried their stuff for them. They wandered around the Himalayas, smoking their pipes, collecting specimens, naming things after themselves.

Nowadays it's different. Any old riff-raff can come. Including me. I'm not climbing, just walking. And I'm coming in from the south, from Nepal, which was closed to my grandad. He approached from Tibet. But we're in the same kind of area, and the big mountain named after the big double glazing company in the middle is the same. So there is a connection, OK?

It's not just anyone who can come, but everyone too – and they do. In the previous month, 10,000 tourists had entered Sagarmatha national park. The trail north from the scary little airstrip at Lukla is chocker with trekkers – at times it's more like a queue than a walk. Antipodeans trade matey banter; purposeful Germans with trekking poles overtake on the straights; the French, beautifully turned out, shrug indifferently; fat tattooed Brits huff and puff on the inclines. Above us, the air is alive with helicopters ferrying Japanese tourists who have neither the time nor the inclination to walk up the valley. They will spend a night in the Hotel Everest View, gasping into oxygen cylinders. In the morning they will take photos on the terrace, then fly away. Tomorrow they'll probably be in Bangkok, or the Philippines.

It's a place of national stereotypes and resentment, as well as brightly coloured hi-tech clothing. It's a Lonely Planet nightmare.

Well it would be a nightmare, if it wasn't also so bloody lovely.

The valley is everything you'd want and more. An icy milky river thunders over rocks and below steep wooded slopes are lush fields where people are working the land, oblivious to the Gore-Tex procession. Oblivious but not unaffected: the houses are smart, the prayer wheels freshly painted, just about everyone has a mobile phone, it seems, and is on it, and there are very few places you can't get a signal around here. This is not really the place to come if you're looking for peace and quiet.

One thing hasn't changed since the days of my grandfather. Sherpa people will carry your stuff for you. Obviously you can do it yourself, but then you're not contributing to the local economy, plus you've got an enormous pack on your back. It's a modern dilemma for today's trekker, who must choose between the weight of weight and the weight of guilt.

Some porters are paid according to what they carry, so carry more in order to make more. There are men on the trails carrying terrifying loads, human yaks basically. I'm on an organised trek, with a company called World Expeditions, which has a 30kg limit for its porters. Better, but I've only got about 3kg – a water bottle, an extra layer, my camera. It's embarrassing.

We're staying in a few lodges but most nights will be spent at World Expeditions' new permanent campsites. This means that we can avoid lodges that burn wood and so trek with an easier conscience. Plus we can avoid some of the busier places – these campsites are mostly in secluded spots away from the trail. And they have lovely big tents, with campbeds in them, even mattresses. Oh and composting loos too (really not bad at all). Yeah it's glamping basically – I'm being led, fed, and put to bed.

There are eight of us in the group, and we have 23 people looking after us. Twenty-three! Our cook, whose name is Tika but who calls himself Mr Yum Yum, produces extraordinary meals – curries, but also pizza, chicken, elaborate puddings, even a chocolate cake, all cooked on a kerosene stove. Yak dung is used for heating. After supper we play cards – Shithead, Goo Kha Tauko in Nepali – with the Sherpas until it's too cold not to be zipped up in a down sleeping bag.

Then, in the morning, BB and Mantre come round with hot tea and warm washing water, before we convene for Mr Yum Yum's porridge. Mmmm, OK, I think I'm getting over my post-colonial angst; that's my bag, the big one over there; lead on, Ang. Ang, a thoughtful man though prone to the occasional attack of the giggles, usually brought on by Goo Kha Tauko is our guide.

We cross the river on hairy high bridges bedecked with streaming prayer scarves, then up through steep woods to a clearing for a first view of 8,848m Everest. That's it, that distant wedge? To be honest it's a bit disappointing from here, but there'll be chances to see it better – and closer – later on. We're not actually going to Everest base camp, which is what most people do – so many people, it's pretty much Glastonbury up there by all accounts. Glaciertonbury, they call it – well, if they don't they should do. Anyway we're going to branch off that trail and head to a place called Gokyo, which has some nice lakes and hills to climb for a fine view over to Everest. Twelve days there and back.

First, though, we need to acclimatise for a couple of nights in the village – practically a town actually – of Namche Bazar. The altitude, even here at Namche (3,440m) is beginning to have an effect. My heart rate and breathing are actually fine, and I'm not getting headaches (come on, I've got Himalayan adventurer in my genes). But my dreams have become extraordinarily vivid and intense. 3D – 4D even – I wake up exhausted. It's similar, though more spectacular, for another member of the group. For Dave, a man in his mid-30s, the altitude turns back the clock at night, all the way to adolescence. Yes, Dave is having those kind of dreams. Twice in one night! I'm not sharing with Dave, thank heaven. Still, it gives us something to talk about at breakfast – it makes a change from comparing cameras, blisters and outdoor gear.

There's a scruffy little Tibetan market here, where you can buy fake stuff from over the border – Hortn Face jackets are my favourite. There's a German bakery too, and an Irish pub, playing Pink Floyd, depressingly. Away from the guest houses, though, the yak bell still rules.

After Namche, the landscape opens out. We've emerged from the valley now, and it's bigger, grander, more spectacular. We're in the mountains proper. There's Everest, still distant and partially hidden behind Lhotse (8,516m), but at least it looks mightier now. Less high, but steeper and more beautiful is Ama Dablam (6,812m). I can see the magnetic pull the mountains have, can understand why those early tweeded chaps like my grandfather came here and set about planning how to overcome them. Especially the big one of course. It still took 32 years, from that first reconnaissance expedition to Everest's eventual conquest by Tenzing and Hillary in 1953. Now, of course, the queue goes all the way to the top. Practically.

We're still passing through settlements, at 4,000m, full of people going about their business. In the village of Mong, I give the prayer wheel and extra spin to purify the soul of Ricky Gervais. There are still plenty of trekkers even after we branch off from the route up to base camp. I did think it might feel more like a wilderness. And if I come back again to walk in the Himalayas, which I hope I will, I will go to a less popular part. But – and it's a big but – there is a reason why people are here. Well, Everest for one, the highest mountain in the world. But also the staggering, spectacular beauty.

The lakes at Gokyo are green and cold. We get up early to climb Gokyo Ri, the hill above, for the famous view. There isn't one today though: it's clouded over. I can't take the photograph I was going to, to hang at the top of the stairs next to my grandfather's. "At 17,500 feet with Everest in the distance. Photograph SJ Wollaston, 2011" the caption might have said. It doesn't matter. It wouldn't have been from where he took his; that was round the other side. And it's still pretty incredible here, even in cloud.

I do find him, on the way back down again. We have another day in Namche, to go and see the yeti scalp at the monastery in nearby Khumjung, to buy yak bells in the market, or to just sit and gaze at Ama Dablam. There's a little museum here, with photos and stuff from the expeditions. Including a picture of the 1921 team. Eight chaps inappropriately dressed in wool and tweed, they look as if they're off salmon fishing in Scotland or something. Sitting on the left is George Mallory, who would die on Everest three years later having possibly – just possibly – climbed it. And standing behind him is a man whose beard can't quite hide the fact that he looks just a tiny bit like me.