The 56 places on UNESCO's 'World Heritage in Danger' list include Historic Centre of Vienna (Austria), Abu Mena (Egypt), Tropical Rainforest Heritage of Sumatra (Indonesia), The Historic Centre of Odesa (Ukraine) and Islands and Protected Areas of the Gulf of California (Mexico). Iraq's Ashur (Qal'at Sherqat), Hatra and Samarra Archaeological City are also on the list.