'Walls' in the Bible

because the days will come when your enemies will build walls around you, surround you, and close you in on every side.

They will level you to the ground you and those who live within your city limits. They will not leave one stone on another within your walls, because you didn't recognize the time when you were visited."

By faith the walls of Jericho fell down after they had been encircled for seven days.

The angel who was talking to me had a gold measuring rod to measure the city, its gates, and its walls.