Near the Hyde Park Corner you can visit the entry of the old Down Street station. It is famous because it was the bunker of Prime Minister Winston Churchill during World War II. You will see the wonderful exterior station designed by Leslie Green. On the contrary, the station interiors retain original signs and decorations.
The station was active from 1907 to 1932 on the Piccadilly Line, between Hyde Park Corner and Green Park. The inhabitants of the rich area of Mayfair, were reluctant to use the underground and so they preferred to go to other stations. Inside the station you can see the still visible signs of the changes during time. To visit this historical station, you have to take part in a Hidden London Tours organized by the London Transport Museum. Unfortunately it is difficult to visit this station, because there are few available dates, scarce tickets and expensive prices .