Overland Kailash Yatra, by Road Both Ways

Acclimatisation, mostly, and money second. Flying to Lhasa puts you at 3,656 m in ninety minutes. Driving from Kathmandu puts you at 1,900 m on the first night, 2,800 m on the second and third, and only reaches 4,640 m on the sixth day. That profile is what the body wants. It is also cheaper, because you are not buying a one-way international flight.

Four routes reach the same mountain. This one drives in and out and is the slowest and the gentlest. Via Lhasa flies in and drives out, and adds the monasteries of the Tibetan capital. Via Beijing comes through China with city time either side and costs the most. The Express uses Simikot and a helicopter and is the shortest, and the least kind at altitude.

Yes, and two of those are days when you barely move: the rest day at Kerung and the spare day after the kora. Both are there for the same reason. Sixteen days is what an overland Kailash journey takes if it is done without rushing the part that hurts people.

Three days, 53 km in total, on paths rather than climbs. The middle day is the one that matters: nine to ten hours, twenty two kilometres, and the Dolma La at 5,630 m. Nobody finds it easy. Fit walkers who have acclimatised properly finish it, and people who arrive underslept and dehydrated often do not.

On the first and third days, yes, and it is arranged at Darchen for roughly $180 to $260 with a handler. On the pass day the horse can carry you only part of the way, because the ground above Shiva Tsal is loose and steep and everybody walks the last of it. Book it the evening before, not on the morning.

You go back the way you came to Darchen with a member of the crew and wait for the group, which usually means one extra night. Nobody is carried over the Dolma La. Turning round on the first day is straightforward, turning round on the pass day is not, which is why the decision is made at Dirapuk in the morning rather than halfway up.

Four, and none of them can be bought individually: a Tibet Travel Permit from the Tourism Bureau, an Alien's Travel Permit, a military permit and a foreign affairs permit, all arranged by us against a paid itinerary. On top of that is the Chinese group visa, issued in Kathmandu. We ask for passport scans at least eight weeks out.

The Kathmandu group visa is issued to a party rather than a person, and the embassy will not issue one to fewer than five travellers. Everyone on it must enter and leave China together, at the same crossing, on the same itinerary. It is the single most common reason a small private Kailash trip falls through.

Not for entering Tibet from Nepal. The embassy in Kathmandu issues a separate group visa on a loose sheet, and obtaining it usually cancels the tourist visa already in your passport. If you hold one and value it, tell us before you book so we can talk through the routing through China instead.

The highest point is the Dolma La at 5,630 m, crossed on the tenth day. The highest place you sleep is Dirapuk at 4,900 m. From Kathmandu at 1,400 m that is spread across nine days, with a rest day at Kerung and a long, slow climb by road, which is as gradual as any Kailash routing manages.

No. There is no helicopter evacuation in the Ngari region of Tibet, and that is the plainest difference between this and a trek in Nepal. If someone has to come down, they come down in a vehicle, on a road, and the nearest hospital worth the name is a long way away. It is why we carry oxygen and a pressure chamber, and why the rest day is not negotiable.

Many pilgrims do, and it helps, but it is a conversation with your own doctor rather than with us. Whatever you decide, it does not replace the things that actually work: gaining height slowly, drinking far more than feels necessary, eating when you have no appetite, and telling your guide the moment you feel wrong rather than at dinner.

May to September, and nothing else. The Dolma La holds snow into May and closes again in October, the kora guesthouses shut for the winter, and Tibet routinely closes to foreign visitors for the whole of March. June to September is the settled window, with September our own favourite for clear air and thinner crowds.

The full moon of the fourth Tibetan month, when the flagpole at Tarboche is lowered and raised again and thousands of pilgrims walk the kora together. It is extraordinary and it is crowded, beds are scarce, and the plateau is at its busiest. Go for the festival or go for the quiet, but know which you have chosen.

Hotels in Kathmandu, Kerung, Saga and Darchen, which are plain but heated and have hot water more often than not. The two nights on the kora, at Dirapuk and Zuthulpuk, are guesthouses: multiple share, a mattress and a quilt, no heating and an outside toilet. They are basic by any standard and they are what exists.

Vegetarian throughout, by convention rather than rule, and better than you expect. Nepali dal bhat on both sides of the border, Tibetan noodle soup and momos, Chinese vegetables and rice in the towns. We carry our own cook and supplies for the plateau, because what is available in Saga at short notice is not much.

It is not a swimming lake. Pilgrims bathe, briefly, as a rite, and the water sits a few degrees above freezing at 4,590 m, so a full immersion is a genuine shock to a body that is already working hard. Do it the way the people around you are doing it: quickly, respectfully and with dry clothes waiting.

The Tibetan side is mostly good tarmac and covers enormous distances, so the long days are dull rather than punishing. The Nepali side, between Kathmandu and the border, is the rough part, and after a heavy monsoon it can be very rough indeed. Take something for motion sickness if you are prone to it.

Wind protection above everything. The plateau is dry and open and the wind is constant, so a windproof shell, a buff and good lip protection matter more than another fleece. Add a four season sleeping bag for the kora guesthouses, and far more sun cream than seems sane at those temperatures.

In the hotels, yes, with a Chinese plug adaptor. On the kora, no. Dirapuk and Zuthulpuk have no reliable power, so bring a battery pack and keep it warm inside your jacket, because the cold empties one faster than use does.

Your Nepali sim stops at the border. Chinese sims work in the towns and not on the kora, and the usual western apps are blocked in China unless you have arranged otherwise before you arrive. Most people treat the eight days on the plateau as time away from all of it, and are glad afterwards.

Rasuwagadhi has closed before, for landslides, for festivals and for politics, sometimes with no notice. If it closes before departure we move you to the Lhasa routing where seats allow, or refund in full. If it closes while we are inside Tibet we come out through the other crossing, and we carry the cost of that, not you.

You get your money back. Permits are occasionally refused for reasons nobody explains, and journalists and anyone whose passport shows certain stamps are refused more often. We do not keep deposits on a refusal that was not your doing.

Two months at the least, and three is better for the June and Saga Dawa departures. The Tibet Travel Permit alone takes eight or nine working days once the itinerary is paid for, the group visa another four, and every Kailash party in Nepal is queueing for the same office in the same short season.