The "Finchley Gap" (or "Finchley depression") is a location in north London which today lies, and which for much of the Pleistocene epoch has lain, between higher ground to the north-west (Mill Hill) and south-east (Hampstead Heath). The term "Finchley Gap" has been used in archeological literature. "Finchley depression" has been used in geomorphological literature. Until the 1960s, it was supposed that the River Thames once flowed through the gap, on a loop running from Harefield to Ware.