Thief III's nighttime adventures take place entirely in the confines of the City, a dense urban expanse that's a medieval fantasy world unto itself. It's a world divided between the rich and the poor, a world of run-down slums and luxurious mansions, castles, and museums. The City is filled with architecture--immense cathedrals, towering spires, scenic rooftops--that might seem remarkable, even startling, if you stopped the thievery long enough to notice. Naturally, Garrett is more comfortable living in the slummy parts of town, where a thief can more easily stay out of sight.