“And of the Underground Fields (though in that age we called them no more than "The Fields") I should set down a little; for they were the mightiest work of this world; so that even the Last Redoubt was but a small thing beside them. An hundred miles deep lay the lowest of the Underground Fields, and was an hundred miles from side to side, every way; and above it there were three hundred and six fields, each one less in area than that beneath; and in this wise they tapered, until the topmost field which lay direct beneath the lowermost floor of the Great Redoubt, was but four miles every way.”