Welcome to Timbuktu, this shadowless town woven around the river bed of the now absent Niger. The river summarily diverted itself elsewhere in the Sahara and has been no nearer than 18 kilometres away since 1979. Fantastic heat alleviated by dashing into the spectacular mud-built Djinguereber mosque. What a cool inducement to pray - long breezy undecorated corridors between the pillars - quiet men kneeling on straw mats while the holy man wails through a humming loudspeaker.
This is the climax to an odd journey - three weeks making a film about the Greenwich meridian and the people who share it. Channel 4, Oxfam, WWF, VSO, Christian Aid and many others have all joined "On The Line" - it's a project to create north/south partnerships and raise awareness about development issues at the dawn of the millennium. It's a simple idea. Look at the Dome and ask - where else will it be 00.00.01 Greenwich Mean Time on the morning of the first day of 2000? In just eight countries - Britain, France, Spain, the imperialist running dogs of this millennium; Algeria, war-torn consequence of some of those dogs; Mali, whose Timbuktu has a university founded at the same time as Oxbridge and which in 1500 boasted 25,000 students and a book trade that outstripped any on earth; Burkina Faso, one of the poorest but most inspiring countries in the world; Togo, nasty little French-backed military dictatorship; and Ghana, coming country of the next millennium. We have camped, bucketed and mosquito-sprayed our way through them all.
Culinary high-spot: in Yendi, northern Ghana, the King of the Dagomba, the Yana, gave us four guinea fowl for dinner. We handed them to Bob, the nice man who ran what posed as the Yendi guest house. They appeared on the table swamped in Kerosene: he had thought the mineral bottles full of lamp-fuel were cooking oil. I still can't understand why the entire Yendi guest house and much of the town weren't engulfed in flames long before supper.
Camping out with the Tuareg nomads north-east of Timbuktu, well into the Sahara, we are completely obliterated by a sand-storm as we attempt to erect our tents at dusk. Sand gets into your teeth, your underpants, your ears - yet when we finally come to eat supper, somehow our drivers have managed to produce couscous without a grain of sand in it.
The Tuaregs are always on or near the line - both the meridian and the poverty line. At least 10,000 Tuareg children are denied education. Sheik Kountor, our tent host, wants us to find some money for a school. I ask him how much two teachers would cost. £500 each, he reckons, and says the entire school could be funded for a year for £5,000. So now we'll have to see if we can find a community further up the line who'd like to help get a school going in the Sahara.
Sanity on this trip is preserved by the BBC's Network Africa - though heaven knows what people here make of the World Service transmission of Last Night of The Proms and a clipped rendition of "Mad Dogs and Englishmen Go Out in the Midday Sun"! Trouble is, one look at us and the Tuaregs know it's only too true.
The wonderfully efficient Burkina Faso air force brings its BAC 748 turbo prop to Timbuktu to save us the 17-hour drive across the desert. That's who you charter if you want a plane in West Africa. The pilots talk proudly of the day they came to Manchester to pick their plane up from British Aerospace. Wherever education has taken root in Mali or Burkina you find this blooming of ability amid the heat and poverty. These chaps would be the envy of Biggin Hill - there's nothing about flying that they don't know. Our Malian fixer, Daouda Ballo, is a schoolteacher who has rarely seen a television documentary, let alone worked on one, yet he's probably the most inspiring, efficient and successful local producer I've ever worked with.
When dreaming up the idea of On The Line with a friend at Oxfam over two years ago, I never for one moment expected to travel it. We talked blithely of children on the line, teachers on the line, journalists on the line - endless partnerships created and sustained by virtue of going on-line.
But I grossly overestimated the state of communications on the line. Only in the Burkina capital did we ever manage to e-mail. Electricity barely exists in many parts this end of the line, the telephone is rare, running water and sanitation are in desperate supply. It's a challenge, not least because there's far more enthusiasm for the project here than I ever imagined - 120 schools in Ghana already partnered, many more in Burkina and Mali, and 4,500 schools applying for On The Line involvement in the UK.
Logging on at the On The Line office in Ouagadougou, I learn that the Millennium Commission is moving ever closer to giving us £1.2 million for an awards scheme that will put the project on the map as never before - so will this film, I hope! A note from the Department for International Development says that George Foulkes wants a chat at the Labour Party conference in Bournemouth: another chance to push the project, but also a sharp reminder that even Ouagadougou cannot escape the lure of Bournemouth. What a culture shock. Maybe, by the time you read this, I will have rinsed some of this sand out of my ears in the Solent!