The Ice Wastes on Mortal Engines world map
The Ice Wastes are the frozen Arctic wastelands in the North. It is the home of the Ice Cities. The Ice Wastes are the main setting of Predator's Gold.
After the Sixty Minute War, the mysterious Pyramid Builders lived in the high Arctic, building their mysterious monuments for unknown reasons. Their civilisation ended hundreds of years before the events of even Fever Crumb. There were also reports of mammoth-like Hairyphants back up in the tundra. The Northern Nomads sometimes rode them to war in the early Traction Era.
Several centuries later, ice cities skated across the ice plains in search of prey. However, the ice grows weak and cracks in summer, which is a danger to the ice cities (which could break the ice with their sheer weight and fall into the icy ocean below). Ice cities move North in the Summertime, where there is still plenty ice. Some are known to even put on tracks and move across the Hunting Ground in the Summer, usually to trade rather than hunt. Whaling Towns also roam the Ice Wastes, drilling holes in the thick ice or, in the cases of lighter, smaller towns, going to the edges of the Ice Wastes that borders with the sea to catch their prey.
Philip Reeve has stated that the sequel to A Web of Air will be set in the Ice Wastes.