the name "ankh-morpork" refers to both the city itself, a walled city about five miles (8 km) across, and the surrounding suburbs and farms of its fiefdom. the city itself lies on the river ankh, the most polluted waterway on the discworld, which divides it into the more affluent ankh and the poorer morpork (including the slum-like "shades".) lying approximately equidistant from the cold, mountainous hub and tropical rim, ankh-morpork is in the discworld's equivalent of the temperate zone.