More than six million tourists visit Bath every year. And after they’ve seen the abbey and the Roman baths and wandered round the Royal Crescent, most of them will venture to the edge of the old town to admire the broad vista down Great Pulteney Street and its enticing termination, the Holburne Museum. But few will realise at first, as they pause to look in the windows of the little shops which flank that view, that they are standing on a bridge over the River Avon. And fewer still will know that this bridge was the work of that giant among Georgian architects, Robert Adam.

Like several of the other bridges described in Benjamin Riley’s elegant new book, the Grade I-listed Pulteney Bridge, designed by Adam to form a link between Bath and the new town of Bathwick and completed by 1774, has been knocked about a bit over the years. It was already in need of repair at the beginning of the 19th century, when the shops along the north side were taken down and rebuilt; it has been restored at least five times since, and at one point Thomas Telford wanted to replace it with a single-span cast-iron bridge, a scheme which never saw the light of day, thank goodness. But if you stroll downriver for a hundred yards or so along Grand Parade and then look back, Adam’s creation is revealed in all its neoclassical glory: more than just a bridge, it is a monument of neoclassical restraint.

Like all good bridges, Pulteney Bridge is best appreciated from a distance, a fact which raises some perplexing questions about form and function. The notion that Adam’s bridges are primarily about their setting in the landscape (or in this case, the cityscape) rather than their ability to chaperon