This year's World Tourism Day (27 September) theme is Tourism & Sustainable Energy, so we’ve scoured the web for enticing eco-tourism deals. From volunteering at an award-winning orangutan rehabilitation centre in Borneo to sailing the Med on a 50-foot yacht with a sustainable tour operator, eco deals aren’t as rare -- or as expensive -- as you might think.

We’ve compiled a list of the best deals, researched and test booked by our Deal Experts, so you can rest easy knowing that you’re doing some good on your holiday.