The term 'Heidi Setting' is a reference to the classic children's novel Heidi by Johanna Spyri. The novel is set in the Swiss ALPS, which can be represented by the crossword solution ALPS. The novel follows the story of an orphaned girl named Heidi who is sent to live with her grandfather in the Swiss ALPS. The novel is known for its beautiful descriptions of the alpine landscape and Heidi's adventures in the mountains.