"Flatenbadet" - is a lakeside beach and camping area not more than 10 km south of central Stockholm. The beach and the cabins were constructed in the early 1930s. It seems it was very popular with people from the working class around Stockholm from the start and through the 60s. After that, with rising wealth, people being able to afford cars and charter vacations abroad, the attraction of Flatenbadet has steadily declined. In the 60s it was for different reasons no longer allowed to live in the very simple semi-permanent "tent-cabins" that were scattered all over the nearby forest. Evidence of their former existence are still found, in the shape of foundations and old stoves.
This is in Swedish but there are some nice vintage photos to see: "Om Flaten och Flatenbadet"
(click the links for the different chapters, not the links to the left)