According to UNESCO, the Rwandan genocide of 1994 claimed the lives of an estimated one million people, mostly of the Tutsi minority group. Now, four memorial sites dedicated to its victims – at Nyamata, Murambi, Gisozi and Bisesero (pictured) – have collectively been made a World Heritage Site. Two of the memorials, Nyamata and Murambi, commemorate massacres committed on the hills on which they stand, while more than 250,000 victims lie entombed at Gisozi in Rwanda’s capital Kigali.