My son’s plan to walk through London along both banks of the Thames was one that appealed to an innate sense of pilgrimage in me, so we decided – on the basis of a cursory look at a very large scale online map, and in denial of any common sense appreciation of the distances involved – to start at Tower Bridge and strike west for Hampton Court as a first stage – before turning back along the south bank and seeing how far we could retrace our steps before it got dark. As plans go, this was on the optimist side.

It was possible to walk from one side of Roman London to the other in less than half an hour and the tourist leg down to Westminster was sunny, busy, studded with statues, well known historical buildings, montages of memories from hundreds of family trips (and demonstrations that assembled on the Embankment) and was almost too familiar.

Beyond Westminster – on the roads less traveled – odd places in Pimlico, like Dolphin Square, emerged in all too solid reality from stories in the papers and Le Carre novels. In Le Carre, Dolphin Square is a place where “the service” retains a number of flats for use by agents. The advantage of this is that it is a huge anonymous looking slab of 1250 expensive, but brutal, 1930s flats, ten storeys high and covering a large acreage; so its easy enough to be obscure in –  and handy for HQ. The disadvantage is that they’ve been doing this for more than 60 years; so you might assume that someone will have noticed – “Mr Bond, oh yes, he’s a regular” – even if they don’t read Le Carre.

Further on, along Chelsea embankment, there’s a long stretch on both sides of the river which have been redeveloped with the sort of buildings that look like they belong in a Dan Dare cartoon strip as the sort of place Venusians might live in. Although some of them seem to have been “sold” there was a distinct absence of people – and a feeling that real people would just spoil the clean, unused – still in their cellophane – feel of the buildings – at least as far as their property values are concerned. An enormous amount of effort and capital is going into building neighbourhoods that exude hostility to neighbourliness. On one street there was actually a  manned checkpoint keeping out cars without permits.