This photograph is dated 30th September 1938.
Harrison Park long trench was 125 yards long and one of many air raid shelters built for the public throughout Edinburgh.
To protect people from the bombing 30,000 public and 110,000 private air raid shelters were built. These were known as Anderson shelters and were built almost underground – six feet down and covered with earth and grass. Some people grew vegetables on the top. Because they were underground many would fill up with water making them damp, cold, smelly places to be. Children often had the job of checking the shelters and bailing the water out.