Now we know what it should look like and what it's made out of, how much it should cost and how long it should take:
Turkey has been quietly building walls on its borders with Syria, Iran and Iraq.
Turkey’s ‘great wall’ nearing completion
http://al-monitor.com/pulse/originals/2017/07/turkey-syria-security-wall-under-construction-border-area.html
Excerpts:
$400 million project.
Reinforced concrete blocks are 9 feet high, 6 feet wide, 11 inches thick and weigh some 7 tons each. These concrete blocks are movable. Barbed wires top the blocks, and there are about 120 observation towers in critical locations.
The towers are equipped with land infiltration radars, night vision systems and advanced weapons. There is a ditch immediately in front of the wall and a road behind it for patrolling and to allow quick intervention if needed.
as soon as the wall is completed, there will be a transition to the second phase: “We are transforming it to an integrated security system. It will not be made up only by the wall, the road and illumination. They will be backed up by fiber optic sensors, cameras, observation balloons and unmanned aerial vehicles to make it a total integrated system.”