The original territory of the Shire was bounded on the east by the Baranduin River, on the north by uplands rising to the old centre of Arnor, on the west by the White Downs, and on the south by marshland south of the River Shirebourne. After the original settlement, hobbits also expanded to the east into Buckland between the Baranduin and the Old Forest, and (much later) to the west into the Westmarch between the White Downs and the Tower Hills.