Exmouth Market in Clerkenwell is one of the trendiest streets in London, its pavement cafes being patronised equally by shirtless men with fighting dogs and refined types who might be Ralph Fiennes. Having been asked to review volume 47 of the Survey of London, Northern Clerkenwell and Pentonville (see page 139), I spent a happy Saturday exploring the area.

Exmouth Market may, as a market, have been ‘working class’, but in the 18th century, it seems to have been occupied by the same sort of arty crowd that it attracts now. Sadler’s Wells theatre is a short step away. Sadler’s Wells, Clerkenwell the names alone should give the clue to another aspect of the area’s past.

There were springs here, which in turn became spas. The open space of Spa Fields is a survival. Perhaps the fabric of any city contains coded memories of this kind, but they seem specially striking in a metropolis as big as London. You can be caught out, however. Our own street, Tachbrook Street, does follow the line of a watercourse (a notorious 19th-century sewer), but not the brook I’d imagined. Our part of Pimlico was once the gardener Henry Wise’s nursery. He came from Tachbrook in Warwickshire.