Strength of Stones
From back cover of Millennium paperback published Great Britain 1999  ISBN 1857989031:

THEY WERE BUILT TO HOLD THE HOPES OF MANKIND.  THEY EXPOSED ONLY HIS FOLLY...

In the deserts of God_Does_Battle the Cities stand alone, as beleaguered as the aspirations of mankind.  Those still alive are silent -- like stars in a dying universe, they await dust and decay.  Yet within the living plasm of their fragmented structures an ancient programme still works, implanted by the human creators cast out a thousand years ago.  Before long, it is clear, some of the Cities will be fighting extinction.  And many of them will do battle in a quite unexpected way...
Science Fiction, Fiction, Fiction, science fiction, general, Fiction, fantasy, general, Perrin, michael (fictitious character), fiction
Greg Bear, Ray Chase
Gregory Dale Bear (born August 20, 1951) is an American writer and illustrator best known for science fiction. His work has covered themes of galactic conflict (Forge of God books), artificial universes (The Way series), consciousness and cultural practices (Queen of Angels), and accelerated evolution (Blood Music, Darwin's Radio, and Darwin's Children). His most recent work is the 2021 novel The Unfinished Land. Greg Bear has written over 50 books in total. Greg Bear was also one of the five co-founders of the San Diego Comic-Con. [source](https://en.wikipedia.org/wiki/Greg_Bear)