Revelation 21:13-16

three gates on the east, three gates on the north, three gates on the south, and three gates on the west. Now the wall of the city had twelve foundations, and on them were the names of the twelve apostles of the Lamb. And he who talked with me had a gold reed to measure the city, its gates, and its wall. The city is laid out as a square; its length is as great as its breadth. And he measured the city with the reed: twelve thousand furlongs. Its length, breadth, and height are equal.