Kenilworth Castle in Warwickshire is not much more than a picturesque ruin but once it was home to Lord Robert Dudley who, in 1575, built a garden for a visit by Elizabeth I. Only one piece of written evidence survives about how it looked, which includes details of an obelisk and a fountain as the centrepiece, so in an attempt by English Heritage to re-create the original, problems of all sorts have arisen. Has the historical validity of the exercise been undermined?