Nodnol was a city on the backwards Earth, it was the reverse counterpart of London. Nodnol is never actually seen in Backwards, just referenced on a sign first spotted by Kryten and Rimmer, then Lister and The Cat which says they are 178 miles from Nodnol. Kryten and Rimmer correctly deduce that they are on a backwards version of Earth in the year 3991 (1993), while Lister and the Cat believe that they are in Bulgaria. They seem to have actually travelled to Retsehcnam (Manchester), as evidenced by the accents of most of its inhabitants, notable local landmarks and Manchester being roughly 178 miles from London. Presumably the city's history is the same as its forward counterpart, except in reverse.