Revelation 21:12-14

12It had a massive and high wall, with twelve [large] gates, and at the gates [were stationed] twelve angels; and on the gates the names of the twelve tribes of the sons of Israel were written.

13On the east side [there were] three gates, on the north three gates, on the south three gates, and on the west three gates.

14And the wall of the city had twelve foundation stones, and on them the twelve names of the twelve apostles of the Lamb (Christ).