Eternity (location)

Eternity was the home of the Eternals. Striker described it as being "endless wastes", and the White Guardian called it an "echoing void". During the race for Enlightenment, any Eternal whose ship was destroyed by Wrack or were thrown overboard were sent back to Eternity. After the race was won by the Fifth Doctor and Turlough, the White Guardian sent the remaining Eternals back to Eternity. (TV: Enlightenment)

Behind the Scenes
An idea among fans, and presented on an extra feature on the Enlightenment DVD, is that the Eternals actually exist in the Void, which Army of Ghosts established they called "the Howling."

Eternidade