It is known as the world's largest refugee camp and is home to more than 400,000 Somali refugees. Most of them came to Dadaab more than 20 years ago. One of them is Siyad Mohamed. He was born and grew up in Dadaab. But this could soon be over. The governments of Kenya, Somalia and the UNHCR have decided that the time had come for him and other refugees to go back to Somalia.