Cities were surrounded by walls, as distinguished from "unwalled villages" (Eze 38:11; Le 25:29-34). They were made thick and strong (Nu 13:28; De 3:5). Among the Jews walls were built of stone, some of those in the temple being of great size (1Ki 6:7; 7:9-12; 20:30; Mr 13:1-2). The term is used metaphorically of security and safety (Isa 26:1; 60:18; Re 21:12-20). (See Fence.)
And as he came out of the temple, one of his disciples said to him, "Look, Teacher, what wonderful stones and what wonderful buildings!" And Jesus said to him, "Do you see all these great buildings? There will not be left here one stone upon another, that will not be thrown down."
It had a great, high wall, with twelve gates, and at the gates twelve angels, and on the gates were written the names of the twelve tribes of the sons of Israel. There were three gates on the east, three gates on the north, three gates on the south, and three gates on the west. read more. And the wall of the city had twelve foundations, and on them were the twelve names of the twelve apostles of the Lamb. The one who talked with me had a gold measuring rod to measure the city, and its gates and its walls. The city is laid out as a square, and its length is as great as the width; and he measured the city with the rod, twelve thousand stadia; its length and width and height are equal. He also measured its wall, a hundred and forty-four cubits by a man's measure, which is also an angel's. The wall was made of jasper, and the city of pure gold, as clear as glass. The foundations of the city wall were adorned with every kind of precious stone. The first foundation was jasper, the second sapphire, the third chalcedony, the fourth emerald, the fifth sardonyx, the sixth carnelian, the seventh chrysolite, the eighth beryl, the ninth topaz, the tenth chrysoprase, the eleventh jacinth, and the twelfth amethyst.