A Green Day Out?
The Guardian has published its top ten green days out, of which I've been to 6 - The Eden Project (great but only green-ish), A Farmers Market, Nature's World Middlesbrough, Brighton Earthship, BTCV Tasks (many... I used to lead some), and best of them all, The Centre for Alternative Technology or CAT in Wales.
To me CAT is amazing, both in location, its content, and its longevity, having been established in the 70s. Compared to the slighty empty flashiness of the now defunct Doncaster Earth Centre, CAT has honed its message to eradicate preachiness and made everything fun, fun, fun. When I was there about four years ago it was swarming with kids running riot (in a good way). It has been revamped recently and I'm keen to back for another look.