What made me, finally, lift the phone and punch in the Drax number? Why now? Because it has just got better and better. Every time I see it, I like it more. Not least because we just don't make 'em like that today. Drax is the last, biggest and best of its breed, a survivor from that murky period known as the recent past. Drax is prime minister Harold Wilson's "white heat of technology". Drax is the long-dismantled Central Electricity Generating Board. Drax is cock-of-the-walk, job-for-life, hold-the-country-to-ransom miners. Drax is Polaris submarines and Concorde and 3-litre Rovers with deep leather seats and Smiths dials. Drax is pre-Thatcher, Old Labour. Drax is history, a fossil burning fossil fuel, yet it lives. And it has a power that is different from the stuff it sends out along wires. And I know I'm not alone in this. Sculptor Anthony Gormley, he of the Angel of the North, is a big fan of Drax. For him, it is "a man-made volcano".

See it from the high ground of the wolds to the east and there it sits below you in the Vale of York, the leader of a pack of several big power stations in the area, together comprising the engine room of England. See it from the vast span of the Humber Bridge, and its steaming presence in the upstream distance could be the source of the river itself. It also sits on one of the great modern crossroads, where the north-south motorways of the M1 and M18 meet the east-west motorway of the M62. There is something compelling about this juxtaposition of heavy industry with carefully-tended nature. The weaving-together of the flat fields and hedgerows with the tall, effortlessly elegant functional shapes and the forking roads. The mysterious silence of it all. These places are not just our Stonehenge. They are our Avebury, our Silbury Hill, our Carnac. Imagine them as ruins, centuries hence. What will our descendants make of them?

Picture a traveller on horseback in some postindustrial Mad Max era, cantering through the sprouting vegetation of the long-abandoned M18. He glances up to see a celestial vision. The sun suddenly shafts through the dark rain clouds, illuminating two great rings of lichen-encrusted sarsens. One ring is a perfect circle, the other an oval. Midway between them, rising from the ruins of abandoned buildings of staggering size, is an obelisk. 850 feet tall and 90 feet in diameter. Behind them is a huge flat circular compound enclosed by an earthwork, and behind that a geometrically-perfect flat-topped wooded mound, covering several hectares, good hunting country, rich in hares and deer. The whole mysterious complex, from colossal towers to enduring marks in the earth, covers 1,854 acres What might all this mean? Why would it have been built? Was it some kind of military garrison, placed to command not only the roads but also the confluence of the Ouse and the Derwent? Was it some astronomical device, a colossal timepiece or calculator? As it happens, Drax is an Anglo-Saxon name, taken from a nearby village. Like the Anglo-Saxon poet musing on the Roman ruins of Bath, our future horseman would assume that this was the work of giants, some vanished race of supermen.

And this was pretty much the feeling I got when I finally negotiated my permissions, got up close, and went inside. Yes, a vanished race of supermen. Engineers and architects of a centralized, nationalized, power-generating system. Where the nation owned the coal and built the power stations and the National Grid to distribute the electricity. It was us. We did that, we - or our immediate forbears - were the giants. It was nothing special, all in a day's work. I met some of them there, men who had been involved at the start. Drax did not even have an opening ceremony, they told me. It just came on stream, 30 years ago in 1974, having been planned since the mid 1960s. First half was built and switched on, then they started building the second half, which had a momentum even prime minister Margaret Thatcher, assiduously seeking alternatives to coal, could not stop. The final part opened in the mid 1980s. Just like that. OK so it was big. No need to make a fuss about it.

You can run through all the political arguments for as long as you like but you keep coming up against an inescapable fact - we're just not set up to do this kind of thing any more. It's unfashionable, even unthinkable in an economy now based almost entirely on people looking at screens. Like shipbuilding, or steelmaking, the careful planning and building of a national power system is one of those remarkable things requiring titanic skills now all but lost. Drax, like the motorways, sprang from the economics of predict-and-provide, with a big generating contingency reserve built into the calculations. We are now firmly in the era of make-do-and-mend, reduced margins, sweating the remaining assets for all they're worth. So Drax and its kin had better go on working, and let's hope we don't forget how to push the buttons and pull the levers. Otherwise all our screens will fade to black.