It was, and remains, the first Modernist phallus in British architecture, pre-dating by more than 35 years Norman Foster's forthcoming Erotic Gherkin and - what larks! - the glinting testicular bulge near Bankside that will soon house the bureaucratic gametes of the Greater London Authority.
But the Post Office Tower - as those of us who remember its erection will always think of what is now the BT Tower - holds an ace card that those sophisticated arrivistes cannot claim: a kind of shock value whose potency has nothing to do with a desire to provoke outrage or admiration. To this day, it remains surprising - wonderfully or horribly, depending on taste. It has nothing to do with the established order of things, then or now. It carries the unmistakable vibe of a roguish one-off.
Such who're-you-looking-at-Jimmy architectural statements do not encourage effective questions. One looks at them, and the mind goes curiously blank. How can you think about something that is, in a sense, unthinkable? In the case of the Post Office Tower, it's a physical thing.
There are dozens of chunks and fillets of London that contain remarkably ugly buildings, structures that are packed with reason but very little rhyme. And when the tower was opened by Harold Wilson in 1965 (four and a bit years after building commenced, in the summer of 1961), the public consensus was that this was a monument to ugliness. Yet how odd that something once thought highly peculiar can lose its ability to nauseate or enrage - and, in the case of this tower, gain a hold on public affection.
When the architecturally brutalist South Bank development first raised its concrete fist over the Thames, it appalled a great many people. But who now gives the affront of those rough, angularly knuckled facades a second look? In the accelerating future of cyberspace mindsets, the South Bank is Old Ugly and therefore wallpaper. Only New Ugly - the Dome? Portcullis House? - is worth a fleeting thought in the cascade of even more newly horrible or beautiful buildings and objects that can be consumed and quickly forgotten.
The Post Office Tower, however, begs to differ. It's an obdurate so- and-so of a thing. It has no immediately obvious beauty, yet it retains the power to move. It is as uncompromisingly "unaesthetic" as other utterly ugly Modernist buildings. Like the British Telecom Research Centre at Martlesham, in Suffolk (try driving past that without flinching), it radiates only function. But it offers another, more powerful perceptual whammy: it's inscrutable. You can look up the length of it, minutely, and not have the faintest idea of what's going on inside; nor any sense of its internal layout or its atmosphere. Only the transmission dishes, growing out of the bulging head of the thing, like techno-weeds, give the game away.
In functional terms, the tower's heyday has passed. It forms an important part of BT's broadcast services, but that part is now invisible. It is no longer open to the public: even its Top of the Tower restaurant, opened by Antony Wedgwood Benn and Sir Billy Butlin in 1966, has closed. The progress from Post Office Tower to London Telecom Tower to BT Tower has also been a progress toward obscurity. Yet in architectural terms - as a landmark - it has, if anything, grown in stature.
In the 1960s, it was one of hundreds of new buildings needed by the Post Office in the aftermath of the Second World War. At 500ft, it was smaller than the Eiffel Tower, while batting on the same futurist wicket as similar structures in Seattle, Vienna and Berlin. Despite its riskiness - the curtain-walling is Jurassic by today's standards - it has proved considerably tougher than, say, the 19- storey "standard" slab-blocks designed by Bedford for the Department of the Environment shortly afterward.
The philosopher Roger Scruton would presumably want the Post Office Tower demolished. …