It does have massive, and all encompassing walls. They aren't built like how we used to build defensive walls in history, those are obsolete. Instead they are lined with chainlink and razor wire, contain radar and other systems for across the horizon detection, have runways for aircraft, silos for ballistic missiles, magazines for gunships, missile carriers, submarines, satellites and other craft in outer space with classified capabilities, entire datacenters. It is one of the most well defended positions in human history.

Right, the silo fields in North Dakota are obviously part of the great wall of Los Angeles. Ask any citizen of Fargo and they will confirm that they are indeed proud bricks in the great Angelino wall and renounce any claim to living in a city themselves.

/s

The absolutely are, though. Not just LA, of course, but for all American cities.

Some are much closer and in LA county or parts adjacent.

It truly would not be a safe settlement without the great Angeline Walls keeping Los Gigantes out from the north.

The two fundamental requirements for a city are:

1) a source of water,

2) a palace or other place to center an economy, and

3) to be enclosed in walls.

We know the last because we have yet to discover any traces of the walls of any unwalled cities.