BeWILDerwood, Norfolk
Family adventure park inspired by the book A Boggle At BeWILDerwood, by local children's author Tom Blofeld. For kids it is den heaven: treehouses, zip wires, jungle bridges, boat trips and marsh walks. Over 70% of waste is recycled and the park has planted more than 14,000 trees and upgraded local footpaths, bridleways and cycle paths.
01603 783900, bewilderwood.co.uk. From £7-£11.
GreenWood Forest Park, Wales
Set in the foothills of Snowdonia, this family adventure park offers rides, boat trips, magicians, face painting and craft making. Pride of place is the Green Dragon Rollercoaster, which uses the gravitational weight of visitors plunging downhill to pull the empty funicular cabins uphill. Arrive on foot or by bike, and you'll be given a free drink, while local school groups who walk to the park are given free entry.
01248 671493, greenwoodforestpark.co.uk. Adult £6.85, child £5.75.
New Lanark Visitor Centre, Scotland
New Lanark is a restored 18th-century cotton-mill village and World Heritage Site that acts as a gateway to the Falls of Clyde wildlife reserve. Its visitor centre has been awarded Gold from the Green Tourism Business Scheme. A hydro-power turbine provides the energy to support 400,000 annual visitors.
01555 661345, newlanark.org. Adult £6.95, child £5.95.
The Deep Aquarium, Hull
The huge aquarium housed in Sir Terry Farrel's innovative glass and aluminium building overlooking the Humber Estuary is both a museum and an environmental and educational charity. The centre is divided into more than 30 exhibits, from shallow tropical seas to the icy depths of the ocean, and is home to more than 3,500 fish including rays, octopus and 40 kinds of sharks. Green initiatives from 2005-2008 have reduced its draw on energy by a quarter.
01482 381000, thedeep.co.uk. Adult £9.50, child £7.50.
Goodleaf Tree Climbing, Isle of Wight
Learn how to climb 60ft oaks at this tree-climbing centre in secluded woodland and you'll be rewarded with views across the Solent. You're given a safety brief and lesson in tying knots, then strapped into a harness and shown how to shinny up. Five percent discount if you arrive on foot, by bike or public transport, and a percentage of the company's profit is donated to Trees for life (treesforlife.org.uk), which works to restore the Caledonian Forest in the Scottish Highlands.
0333 800 1188, goodleaf.co.uk 2½-hour group session: adult £35, 8-16 year-olds £25.
Zealandia, New Zealand
A wildlife-rich square mile, minutes from downtown Wellington, Zealandia (formerly known as the Karori Sanctuary) is part of an ambitious 500-year vision to restore native forest and wetlands to New Zealand's mainland. It's one of the best places in the country to see the elusive, flightless kiwi, especially if you go on one of the guided boat trips in the early evening.
+64 4 920 9200, visitzealandia.com. Open 7 days, 10am-5pm. Admission adult NZ$15 (around £6.75), child (5-16yrs) $7 (£3.15), family $37 (£16.60).
Greenheart, Ibiza
Ibiza's flagship ecology and family education centre is run by volunteers at a farm, Casita Verde, a few kilometres northwest of San José. You can leave the kids in a supervised play school while you stroll around the centre, learning the ins and outs of alternative technologies and how to cultivate plants and herbs. If that sounds a tad serious for a holiday, you could just chill out with a massage at the natural therapy centre or sit drinking a healthy dose of Cassita's own organic carob syrup, looking out over the valley.
+34 971 187353, greenheart.info. Open Sundays only, 2pm-6pm. ¤5, bring ID.