Migrants who wish to travel legally are rarely free to go wherever they want. Their movements are governed by a raft of rules, conventions and regulations that determine who may go where. But, equally, international agreements can give migrants significant rights to settle.
The photo is grainy and coloured in the lurid grey-green of night-vision camera equipment. It shows two parallel wire fences, each perhaps more than three metres tall. The fence on the left is topped with coils of barbed wire. Standing against it are a number of rough ladders on which some men are climbing. A few have reached the top; more stand behind, waiting their turn.
Strange as it may seem, if the men make it across ...