Revelation 21:13-16

on the east were three gates; and on the north three gates; and on the south three gates; and on the west three gates. And the wall of the city had twelve foundations, and on them twelve names of the twelve apostles of the Lamb. And he that spake with me had for a measure a golden reed to measure the city, and the gates thereof, and the wall thereof. And the city lieth foursquare, and the length thereof is as great as the breadth: and he measured the city with the reed, twelve thousand furlongs: the length and the breadth and the height thereof are equal.