Low impact mountain biking holidays run by English owners in the Sierra Nevada in Southern Spain. Trips are based at a mountain cortijo (traditional stone farmhouse) at an altitude of 1700m from where you have the choice of taking the high mountain route or dropping down to the verdant valleys of the Alpujarras. The remote setting means that everything is run off-grid: power is provided by solar panels (a wind turbine is planned), water is from a natural spring and waste is recycled or composted.
Presented on the "Guardian Green Travel List 2010 - http://www.greentraveller.co.uk/content/green-travel-list-full-0