The Aral Sea is notoriously regarded as the worlds worst man-made environmental disaster. This vast inland sea has halved in depth and lost 90 percent of its volume. Once thriving fishing ports are 50 kilometres from the sea and ships lie stranded in the salty desert. With World Bank help, the Kazakh government has built a massive 12-kilometre dam. Now water is returning to one half of the sea – but beyond the dam the other half remains dried up desert.