It had a great, high wall with twelve gates, and with twelve angels at the gates. On the gates were written the names of the twelve tribes of Israel.
References for Revelation 21:12
There were three gates on the east, three on the north, three on the south and three on the west.
The wall of the city had twelve foundations, and on them were the names of the twelve apostles of the Lamb.
References for Revelation 21:14
The angel who talked with me had a measuring rod of gold to measure the city, its gates and its walls.
References for Revelation 21:15
The city was laid out like a square, as long as it was wide. He measured the city with the rod and found it to be 12,000 stadia in length, and as wide and high as it is long.
References for Revelation 21:16
The angel measured the wall using human measurement, and it was 144 cubits thick.
References for Revelation 21:17
The wall was made of jasper, and the city of pure gold, as pure as glass.
References for Revelation 21:18
The foundations of the city walls were decorated with every kind of precious stone. The first foundation was jasper, the second sapphire, the third agate, the fourth emerald,
References for Revelation 21:19
the fifth onyx, the sixth ruby, the seventh chrysolite, the eighth beryl, the ninth topaz, the tenth turquoise, the eleventh jacinth, and the twelfth amethyst.
References for Revelation 21:20
The twelve gates were twelve pearls, each gate made of a single pearl. The great street of the city was of gold, as pure as transparent glass.
References for Revelation 21:21
I did not see a temple in the city, because the Lord God Almighty and the Lamb are its temple.
References for Revelation 21:22