Aiming for the utmost authenticity, [director Douglas] Camfield hoped to carry out some location filming in the London Underground itself -- specifically, the Aldwych platform on December 15th, and the entrance to Covent Garden on the 17th. Production assistant Gareth Gwenlan duly wrote to London Transport on November 7th seeking the appropriate permissions. Unfortunately, London Transport demanded an exorbitant fee, and indicated that filming would be restricted to just a handful of overnight hours. Instead, the decision was made to replicate the Underground in the studio, on sets designed by David Myerscough-Jones.
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Midway through the broadcast of The Web Of Fear, the BBC received a complaint from London Transport. They accused Camfield of having somehow contrived to film in the Underground, without permission or payment. Eventually, London Transport was persuaded that what appeared on screen was, in fact, the result of Myerscough-Jones' convincing set design, rather than the fruits of any mischief on the part of the Doctor Who team.