North of him the ground was level; flat as the top of a table. But at the centre, due north of him, the ground rose from that flatness in a perfectly symmetrical, rising and curving, concave spire. It narrowed and narrowed reaching up, growing ever more slender, rising so high that it was impossible to see where it ended. He saw it in a multitude of colours. There were broad areas of brown and yellow, patched with green further north there was a blueness: a pure sapphire blue, bright on the eyes
Christopher Priest – Inverted World