3 ft 6 in gauge railways in the United Kingdom
One of the first railways using 3 ft 6 in (1,067 mm) gauge track was the Little Eaton Gangway in England, constructed as a horse-drawn wagonway in 1795. Other 3 ft 6 in (1,067 mm) gauge wagonways in England and Wales were also built in the early 19th century.
Source: Wikipedia — 3 ft 6 in gauge railways in the United Kingdom (CC BY-SA 4.0)