The River Crane, a tributary of the River Thames, runs through part of west London, England, historically the former county of Middlesex. The Crane flows 8.5 miles (13.6 km) through three London boroughs: Hillingdon, Hounslow and Richmond upon Thames. The drainage basin is heavily urbanised but the immediate old flood-meadows of the Crane Valley are a main "river corridor" in London – a continuous belt of semi-natural habitat.