Ham-on-Rye
Ham-on-Rye is a town in the Shires, the border area between Quirm and Ankh-Morpork. It is famous for its therapeutic mineral baths, and for its theological college, an establishment which despite its possibly unfortunate name has turned out a goodly number of priests, including the current Bishop of Quirm. The name must have taunted Sam Vimes, a man craving a bacon sandwich.
Annotation
In the real world there is a Ham about 5 miles from Sandwich, Kent, annoyingly in the Parish of Northbourne. It may be a reference to Hay-on-Wye, a town famed for its literary festivals.