Rev. 21:1-2a "And I saw a new heaven and a new earth...and I saw the holy city, new Jerusalem coming down from God out of heaven..."  (This entire chapter is about the "city".)

This is getting good.  All the bad stuff is now over.  And God comes to be with men and "...God shall wipe away all tears from their eyes..."vs. 4   God tells John to write all this down (again)  "Write: for these words are true and faithful." vs. 5

God wants to be sure that future generations will have the written word.  He wants them to know about these things, even if we don't understand it all.  He uses the words "true" and "faithful" any number of times.  He is describing himself.

The last chapter (22) is my favorite.  I understand this chapter.  All the other chapters can get a little fuzzy.

vs. 1 "And he showed me a pure river of water of life, clear as crystal..."

When I was a little girl, we used to go to Saline creek to swim.  The water came from a spring and was as cold as ice.  And pure.  Crystal clear.  You could stand in water up to your chin and count your toes.  ( And shiver.)  It is one of my fondest memories.  But "progress" ruined it.  They built a dam, which covered everything over and around that place and the next generation will never know that it existed.

I think that this river in heaven is going to be like that.  I am definitely going to dip my toes in it.  And I am sure that God isn't going to build any dams to ruin it.