The main and oldest part of the Shire was bordered to the east by the Brandywine River, on the north by uplands rising to the Hills of Evendim, on the west by the Far Downs, and on the south by marshland. It expanded to the east into Buckland between the Brandywine and the Old Forest, and (much later) to the west into the Westmarch between the Far Downs and the Tower Hills.