[pangaea6]

Only 18’ tall? I thought it was gonna be higher.

[dragnet2]

Have you ever attempted to scale an 18' wall of this type? That's a fatal fall, or at least will leave you all broken up on the ground.

When you empty a bag of sugar, there will always be some granules left behind.

And a wall such as this will not stop every single person, but it will clearly stop the majority, tens of millions of others from ever attempting it. That is the idea here.