The worlds of Series Seven are far more mountainous than other worlds.
The world Christopher Chant visits with Tacroy in The Lives of Christopher Chant has towering mountains, among which is a Great Glacier which is a famous attraction, and tropical lowlands with strident green ferns, flowing tropical trees, and violent green moss that grows scarlet cups as big as hats, all dewed with water. The guide who takes Christopher and Tacroy to see the Great Glacier is a gypsy-looking man.
People in Series Seven wear billowing coats that Christopher is reminded of by the gowns worn by Cambridge scholars.
A (different?) world in Series Seven is the setting of Conrad's Fate.