Sor Brook is a chalk-influenced lowland stream flowing through the Oxfordshire countryside in central England, draining southward through the villages of Horley and Broughton before joining the River Cherwell. The brook passes through a predominantly agricultural landscape and is designated as both a Drinking Water Protected Area and a Safeguard Zone, reflecting its importance to the local water supply. The stream supports a diverse community of aquatic invertebrates and coarse fish species throughout its lower reaches, while its upper stretches near Horley are recognized as quality trout habitat. The brook has been classified as an EU Cyprinid fishery in its lower sections, underscoring its value as a mixed coarse and game fishery.