The Anglo-Saxons looked at the Roman ruins that surrounded them and decided these structures must be the work of giants: mere human beings couldn't have built anything so grand and solid. Mitchell and Robinson write that "In both their poetry and their prose the Anglo-Saxons were very given to reflection on former civilizations and the people who built them, so much so that their language had a word for such meditation: dustsceawung, 'contemplation of the dust.'" I'm reading The Silver Chair to the fifth grade, and it occurred to me that the "ruined city of the giants" owes something to this Anglo-Saxon misapprehension. The same goes for the city of Jadis, in The Magician's Nephew.