The fictional island in The Railway Series is Sodor, usually called the Island of Sodor. It is the main setting for Wilbert Awdry’s stories about Thomas the Tank Engine and the other locomotives.
Sodor is presented as an island in the Irish Sea, positioned between the Isle of Man and the English county of Cumbria. It contains towns, industries, mountains, harbors, and an extensive railway network. Tidmouth is its largest town, while Suddery is described as the capital.
Wilbert Awdry invented Sodor while telling railway stories to his son Christopher, who was ill with measles in 1943. Awdry and his brother George later developed the island’s geography, history, and language in considerable detail. The name is not a typo for “Sod”; it was inspired by the historic Diocese of Sodor and Man.