I saw the Spire on a wonderful clear winter's day. The low sunlight glimmered off the slightly matt finish of the stainless steel, dematerializing it slightly. I imagine that on misty days it will vanish altogether. People instinctively gather round it. It is not visible from everywhere - this is very much a central-city thing - and some of the glimpses you get of it from afar are misleading. Seen above intervening buildings, it can even be mistaken for a flagpole or TV mast. By the time you get south of the river to Trinity College, its impact has faded. It scarcely impinges on Temple Bar, the frantically busy regenerated wharfside area that is like a mix of London's Covent Garden and Clerkenwell. But it defines the city centre, axially and absolutely. As with all true landmarks, you can navigate by it.