The Evacuated Zone, or Central Zone, (PROSE: Doctor Who and the Dinosaur Invasion) was an area of London that was evacuated in the 1970s after dinosaurs began appearing, brought through time eddys by Whitaker's Time Scoop as a part of Operation Golden Age.
Eight million people had to be relocated and the Government moved to Harrogate. The zone became redundant when the dinosaurs stopped appearing; Whitaker and his co-conspirator Sir Charles Grover having been sent into the past. (TV: Invasion of the Dinosaurs)