Gloucester was an English city. The Eleventh Doctor once suggested to go there in an effort to stop the Atraxi from destroying the world in their search for Prisoner Zero, but was put off the idea because the city wasn't actually reachable given the time and tools he had available. It was a half-hour drive from Leadworth. (TV: The Eleventh Hour)
West Country Children's Home was located in Gloucester. The Twelfth Doctor and Clara visited it in the 1990s and saw Danny Pink as a child. Clara also claimed that she had never been to Gloucester but the Doctor ignored it, saying that she had likely simply forgotten. (TV: Listen)