Gallifrey Falls No More

 was a piece of art, showing Gallifrey in the final days of the Last Great Time War. Originally thought to depict the end of Gallifrey, it turned out to save Gallifrey, as it showed the pocket dimension Gallifrey was in. It was believed to have two titles, "Gallifrey Falls"/"No More", but the curator of the National Gallery knew its true title and purpose. (TV: The Day of the Doctor)