Silent Pool

The  was a lake near the Edison manor in England. In 1927, Agatha Christie, the Tenth Doctor and Donna Noble drowned the Vespiform Reverend Golightly in this lake. The next day, Agatha's car was found by the side of the lake. (TV: The Unicorn and the Wasp) The name of the lake is not mentioned in-story, but it's name is on a sign