tanzania: hiking the great rift valley

It is the hardest part of the route, and it is mostly a descent, which is its own kind of hard on the knees.

We grade the highland crossing towards Natron as strenuous and put it at about a day and a half; this route allows two days and camps where each day's walking ends.

The drop is the thing. You leave crater country in the Ngorongoro highlands and finish at a lake whose surface sits at around 600 metres, so the air warms as you go down and the last hours are hot.

The distance is commonly put at around sixteen kilometres, so treat that as a guide rather than a measurement. You need to be comfortable on your feet for several hours over rough, stony ground at a pace set by Maasai guides.

Walking inside the Empakai crater itself requires an armed ranger.

Very hard, and it is the one part of this route that asks for hill fitness you already have.

The volcano stands at 2,962 metres and the walk sets off in the small hours, usually around midnight, so that the summit comes at sunrise and the descent is finished before the heat builds.

The climb gains more than 1,600 metres in about five kilometres, on loose volcanic ash and rock with little to hold on to. The round trip takes twelve to fourteen hours, and we rate it one of the most demanding single day climbs in East Africa.

Nobody goes up without a local guide. If you have any doubt that a climb like this suits you, put it to your own doctor before you book.

Say so if you would rather not: the two Natron days hold plenty without it.

Armed and licensed people throughout, and twelve is the age floor inside the national parks.

Inside the national parks the published fee bands run to adults and to children of twelve and upwards, with nothing below that age, and they split a walk at the four hour mark.

On the Serengeti plains the camp's own guides are rifle trained and go out accompanied by a park ranger, which is the arrangement the park requires. In the Ngorongoro Conservation Area the rule is the conservation authority's rather than the park's, and an armed ranger goes with anyone walking inside the Empakai crater.

At Lake Natron the walking is on a private Maasai concession with Maasai guides and no big game to speak of, which is why the days there feel so different. At Lake Manyara the walks run from a short shore amble to a climb up the escarpment.

That depends on the month, because the camp moves with them.

It stands on the southern short-grass plains near Nabi Hill from December to March, which is when and where the wildebeest calve, and it is taken down and rebuilt near Kogatende and the Mara River from around July to October for the crossings.

Between those two spells the herds are somewhere in the middle of the park and much harder to place, because the pattern follows rainfall and shifts from one year to the next.

In some seasons the camp stays a little longer at each end, south from December into April and north from June, so tell us your dates and we will confirm where it will be standing before anything is booked. Wherever it stands, the walking is the constant.

June to September, and on this route the deciding factor is heat rather than game. Those are the months our own Lake Natron advice rates highest.

In January and February the lake runs above 40 degrees and walking is workable only around dawn and dusk, which is a poor way to spend two days on foot. July to September is also dry in Lake Manyara and the Serengeti, with firm ground underfoot and the northern herds arriving from about July.

October is a fair alternative, hotter at Natron but still good in the parks. The stretch to leave alone is the long rains from March to May, when the highland tracks soften and Manyara is at its wettest.

If your dates are fixed, tell us and we will move the walking hours rather than the route.

A good deal, and none of it from a vehicle.

Natron is a hyper-alkaline soda lake at around 600 metres whose water can exceed a pH of 12, and that chemistry is exactly why it matters. It is the only regular breeding place in East Africa for lesser flamingos, and about three quarters of the world's lesser flamingos are hatched on its evaporite islands, which the caustic water shields from predators.

At dawn you walk out onto the flats where the birds feed, before the day heats up. The other half of the day goes to the Ngare Sero gorge, waded rather than walked, which ends at waterfalls cool enough to swim in.

Days start early and stop early here for a reason: temperatures at the lake are frequently above 40 degrees.