www.Timberplay.com based in Sheffied are the GB distributers for Outdoor natural play specialists Richter -
unitedplay.de the gallery/text is in German but navigation is fairly straight forward & the pictures are fantastic.
CED Ltd - Natural boulders
For general information of local projects, walks and play areas
Groundwork.org.uk is a great starting point.
Does anyone else know of local companies with a gallery/portfolio of images that could help with design ideas ..