<P> Swedish minigolf courses typically had a rectangular wooden frame surrounding the playing area made of tennis field sand (while the American manufacturers used newly developed and patented felt as the surface of their minigolf courses). Felt did not become popular as a surface material in Sweden until in the mid-1960s--but since then it has become practically the only surface material used in Scandinavia and Britain, due to its favorable playing qualities in wet weather . (Minigolf courses with a felt surface can be played in rainy weather, because water soaks through the felt into the ground . The other commonly used surface materials, beton and eternite, cannot be used in rainy weather, because the rainwater pools on them, stopping the ball from rolling .) </P> <P> The Swedish Minigolf Federation (Svenska Bangolfförbundet) was founded in 1937, being the oldest minigolf sport organization in the world . National Swedish championships in minigolf have been played yearly since 1939 . In other countries minigolf sport federations were not founded until the late 1950s, due to the post-war economical depression . </P> <P> In 1954, the minigolf course in Ascona (Switzerland) opened, the oldest course worldwide following the norms of Paul Bongni . </P> <P> The earliest documented minigolf competitions were played in the United States . The first National Tom Thumb Open minigolf tournament was arranged in 1930, with a total cash purse $10,000 (the top prize being $2,000). Qualification play - offs were played in all of the 48 states, and the final competition on Lookout Mountain, Chattanooga, Tennessee attracted over 200 players representing thirty states . After the Depression ten years later, minigolf died out as a competition sport in America, and has begun to recover only during the most recent decades . The American minigolf sport boom of the 1930s inspired many European countries, and the sport of minigolf lived on in Europe even after the American game fell into Depression . They then went on to football . </P>

Where is the world's oldest mini golf course found