128. The tower at Osterley

Ah, if only this really were the top of a London Underground skyscraper, its summit boasting restaurants, swimming pools, viewing platforms and the entrance to a giant chute down which you could slide all the way to the station entrance.

It’s still utterly spectacular, despite possessing none of these things and being the width merely of a mildly stout man.

In fact, I’m not sure you can get inside it at all. I suspect it is entirely filled with concrete. But no matter, for it caps what is an extraordinary tower of beauty sitting in a location of brow-furrowing ordinariness.

The tower’s practical job seems to be as a landmark to help people approaching from a distance. Its job as a piece of architecture is more subjective, and probably rests on your view of European design of the 1930s. That, and whether you find a massive pile of bricks and concrete appealing. Which they are, obviously.

The station was the work of Stanley Heaps, following the style developed by Charles Holden up at the other end of the Piccadilly line. It’s a gloriously imaginative, chic and daring prong of modernism. From a certain height, and in a certain era, it resembles a huge electrical jack or futuristic transmitter, the kind up which diabolical masterminds would send messages to testicle-shaped aliens, and from which monsters and maidens would dangle.

At night those panels on the side of the concrete obelisk light up, making it look even more other-worldly – yet still attractive, even alluring. It’s such a simple idea: build a great big tower then make it even higher. But it’s one that also manages to sum up the combined, intricate appeal of the Underground: its impulsive ambition, its stylish audacity, its pride in being noticed, its joy in being admired.

Not bad for a poke in the sky.