Horsfield and his chief executive, Gerald Wingrove, have been mapping out a 30-year strategy for their ultimate trainset. They know that by 2020, the Government wants to be generating half as much power from coal as it does at present, for environmental reasons. They are unfazed by this. Drax is the biggest and most efficient coal-fired plant there is. So other, older and dirtier, stations will go cold, to be replaced by whatever strange hotch-potch of generating kit is by then deemed acceptable. Drax, though, will stay hot. Perhaps it will eventually have to mothball some of its generators, but - barring total financial meltdown - it will survive. Following on from the smoke cleaning will come a big investment in reducing nitrous oxide emissions. The "carbon trading" game will soon start in earnest, with big players like Drax effectively buying the right to continue burning fuel. Horsfield and Wingrove are meanwhile experimenting with burning renewable biomass as well as coal - waste from crushed olives, and harvested coppiced willow, are the latest wheezes. It is possible that rather than drawing its fuel from beneath Yorkshire, Drax could harvest it from new forests established on the surface. Whatever, it will endure a good few years yet.

But in a way, this is not the point. Everything comes to an end eventually. All industrial processes become obsolete, all factories eventually become museums. Whatever happens to Britain's electricity generating industry - and the chances are we shall have to start thinking nuclear again pretty soon - Drax should remain in its monumental glory. There are not so many functioning temples of old industry left. It's time to start considering them. Take the I.C.I. Teesside chemicals plant - an astonishing sight, glimpsed from the heights of the North York Moors, especially at night. Or the tall silos of the sugar industry near Bury St. Edmunds in Suffolk, the giant flour and grain hoppers of Trafford in Manchester, the forests of long-wave radio masts at Daventry, various military early-warning stations, even the tall-chimneyed cement works that you unexpectedly come across in the Pennines near Bakewell in Derbyshire.

Plenty of places we go to now as tourists and consumers were once crucibles of industry. Ironbridge in Shropshire, the old mines and tramways and mysterious underground waterways of the Peak District, the textile mills of New Lanark outside Glasgow, the Beamish open air industrial museum (formerly the site of a drift coal mine) in Durham, the Baltic art gallery in Gateshead (formerly grain silos) Tate Modern (previously Bankside Power station). There are even signs that the long-running saga of Bankside's sister, Battersea, at present an evocative ruin, is drawing to a close: it will become the centerpiece of a huge new development. A steelworks in Rotherham has become Magna, a highly-successful hands-on science centre. The Black Country is peppered with industrial museums and rides. The sprawling Italianate Lister Mills complex in Bradford is being converted into upmarket homes. A worked-out claypit in Cornwall has become the eco-landmark of the Eden Project. The Georgian canal network, once a heavy goods distribution system, is now a boating paradise. Old steam railways are booming. We are comfortable with all this. We know that industry can convert into something else.

And we should be equally comfortable with Drax and its mighty industrial cohorts. It's just great that such a place, which is so viscerally impressive, should be set to continue operating years into the future. But we should start thinking now about what happens in the longer term. If Drax is truly to be the last "carbon dinosaur" left standing, then let it stand. Do not tear it down to build some banal housing or trading estate. Let it be an object of wonder to the world. Let its private railway line bring awestruck trippers rather than wagons of coal. Let the masses wander through it, and gasp as I did. Take out the flues and put a bigger lift in the chimney than the cramped, clanking miner's cage I endured.

And later still, generations hence, let it continue to exert its increasingly mysterious power. Nobody ever set out to build a modern Stonehenge. They were building a very big power station, they were not sitting down to plan an enduring monument to the society of the late 20th century. But it just so happens that this is exactly what they did. Drax is no trashy Millennium project. It is the real thing. And that is why it should stay there, for ever and a day. Vivat Drax!