This is a good report on recreation in Europe.
A citation would be....
Simon Bell and Liisa Tyrväinen and Tuija Sievänen and Ulrike Pröbstl and Murray Simpson,
"Outdoor Recreation and Nature Tourism: A European Perspective",
Living Rev. Landscape Res. 1, (2007), 2. URL (cited on <29 2014="" jan="">): 29>
http://www.livingreviews.org/lrlr-2007-2
It is important to compare and contrast recreation across the globe.