The white substance on the face of the cliffs is a limestone chalk consisting primarily of the finely ground shells and exoskeletons of marine life.
The white cliffs of Dover were formed undersea during the Cretaceous Period, which began 13.6 million years ago.
Though the World War II era classic "There'll Be Bluebirds Over," made famous by Vera Lynn, couples bluebirds with the white cliffs of Dover, that species of bird is not typically found in the area.
In the James Bond movie "Moonraker," by Ian Flemming, the villain of the story attempts to kill Bond by bombing the cliffs.
