Koalas in Crisis

The team's on Australia's Kangaroo Island, twelve months on from the catastrophic bushfires that killed thousands of koalas; and in Guatemala, where scientists are using laser imaging to reveal more about the Mayan civilisation. Rajan Datar also visits the crumbling Italian hilltop village that's battling to stop erosion carrying away its heritage; and Ade Adepitan heads for the Maldives to explore a side of paradise that tourists don't usually get to see.