Behind a high, black, wooden fence that all but entirely obscures it from view, an old Thames riverboat, now converted to serve as a unique indoor play space for local children, is the centrepiece of what appears to be an abandoned plot of waste ground, left over from a slum clearance in the 1950s or 1960s.

The fence was erected as a precondition for the award of a capital funding grant from an inner-city investment scheme in the 1980s; for this site – deemed unsightly to all but the local children, for whom it is simply ‘the Barge’ – occupies a high-profile position: opposite the famous Old Vic theatre in the Waterloo area of inner London, less than a mile from the Houses of Parliament and even closer to the South Bank arts complex. As if the rusting old boat were not enough, the winers, diners and theatregoers passing by were also subject to the sight of the sprawling, somewhat anarchic homemade wooden structures that children and their playworkers were prone to erecting without apparent consideration of the aesthetic sensibilities the cultural elite – hence the fence.

Today however, this slightly ramshackle place, which is in a process of seemingly endless redevelopment, is being visited, paradoxically, by someone at the pinnacle of this elite: no less than Her Royal Highness Princess Anne, only daughter of the reigning monarch. As a patron of the local charity Blackfriars Settlement, Princess Anne is to visit some of its projects on the occasion of its centenary. One of these is the Barge, otherwise known as Waterloo Adventure Playground.

Sniffer dogs and armed police sweep through the grounds in advance and one of the children has given me (as the senior playworker and site manager) an anxiety attack by claiming that there’s ‘a shooter’ buried somewhere behind the barge. This is not entirely incredible, given the networks of some of the local families whose children attend the facility, including, for example, those of the notorious ‘Great Train Robbers’. No gun is found, however. I can breathe again.

The Princess arrives, and while it is unlikely that a more incongruous scene has been observed in SE1 for many years, she is completely charming, relaxed and interested in the assorted children, staff and parents there to greet her, once she is freed from the accompanying cortège.