But they might now. The hoardings and fences have come down, the space has opened up, a sequence of understated modern buildings along one edge have come into use, £14.5 million has been spent, and it looks good. Tower Hill, regarded by some as the 1,000 year old psychogeographic centre of London, which used to be a confused collection of tacky buildings and kiosks, overgrown shrubs and a rat-run road, has had a benign ordering hand swept across it. It has become a calm, even austere, urban space. It has opened up uninterrupted views of the western flank of the Tower. It will effortlessly absorb the five million people who come to the Tower every year, only half of whom actually go in: the rest hang around having their pictures taken.

This is architecture as landscape and vice versa, and it is designed by architects Alan Stanton and Paul Williams, a pair whose credentials range from designing many an exhibition at the Hayward and the Tate to the creation of the ambitious new public art gallery at Compton Verney in Warwickshire. They are not afraid of tackling sensitive buildings: why, they even braved the late Sir Denys Lasdun in their revamp of the National Theatre a few years back, and in 2002 managed to build an entirely new visitor centre for English Heritage at Whitby Abbey within the derelict shell of a 17th century house. Stanton Williams, with their purist modernist approach, their love of the exquisite detail, are however not yet household names. They admit that they are still chasing that elusive, career-defining big London commission.

For the moment, they will have to make do with Tower Hill, a project that many will probably not regard as architecture at all (it is). This is a World Heritage Site. Despite the fact that over-inflated office blocks and busy highways crowd round on all sides, the precincts of the Tower itself are as close to being sacrosanct as anywhere in Britain. To design anything here is to walk on eggshells: the pair had to consult over 100 different organizations which had a stake in, or opinion on, the place. But what was running in Stanton Williams' favour, when they won the international competition for this project five years ago, was that the Tower's surroundings had become such a mess. A masterplan was drawn up to put it right. The only question was exactly how to go about it.