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...