The Developing City: As part of the London Festival of Architecture, a major exhibition is being held at the Walbrook Building. That's the ribbed-blancmange-type building opposite Cannon Street station, if you're not familiar. One day the lower ground floor of the Walbrook will be retail space selling coffee, chocolates and knickers to the traders working in the offices above, but for now it's a perfect empty canvas for mass informational display. There are three sections to the exhibition - essentially past, present and future - with the emphasis very much on individual buildings and their place in the City. The historical section starts with Londinium, the Roman settlement-on-Thames, and works its way up through medieval and Georgian to the aftermath of the wartime Blitz. If you like maps, you're in for a treat. John Rocque's 1746 map of London, Westminster and Southwark is blown up to enormous proportions at the entrance, from the days when Knightsbridge and Camden were still fields (and some of you could probably spend quarter of an hour staring at this alone). The development of London Bridge gets full treatment (one of the proposals for its 19th century redevelopment was a twin bridge with separate drawbridges, blimey), as do several other key City buildings. Best bring your reading glasses if you wear them, there's a heck of a lot of background to digest on these giant boards. On to the present, which takes a more three-dimensional form. A huge 1:500 scale model of the City is on show, created with the kind of intricate detail that's only possible when you're an age-old settlement built on centuries of mercantile wealth. That's followed by individual scale models of some of London's older and newer skyscrapers, and forthcoming office developments, and any other new building the curators could grab the architects model of. I've seen a few of these before, but never quite so many all gathered together in one place, making for a most interesting potter round. And finally the exhibition looks ahead to 2050 and how the City might look then, based on flights of fancy and evidence-based speculation. I doubt that Farringdon will become a Fleet-side river city, or that Shoreditch will become a fluorescent entertainment hub, but I can well believe that Aldgate is ripe for transformation into the City's new financial skyscraper quarter. Lots to think about, lots to see, and lots of time to get here before the exhibition closes. The last day's Sunday 9th September, and it's open every day except Monday, with late opening on Fridays. Ian's been too and has written a full report with plenty of photos, so that's two recommendations for a visit.