'Gates' in the Bible

I died; but I am now alive until the Ages of the Ages, and I have the keys of the gates of Death and of Hades!

It has a wall, massive and high, with twelve large gates, and in charge of the gates were twelve angels. And overhead, above the gates, names were inscribed which are those of the twelve tribes of the descendants of Israel.

There were three gates on the east, three on the north, three on the south, and three on the west.

Now he who was speaking to me had a measuring-rod of gold, with which to measure the city and its gates and its wall.

And the twelve gates were twelve pearls; each of them consisting of a single pearl. And the main street of the city was made of pure gold, resembling transparent glass.

Blessed are those who wash their robes clean, that they may have a right to the Tree of Life, and may go through the gates into the city.