The River Garnock (Scottish Gaelic: Gairneag / Abhainn Ghairneig), the smallest of Ayrshire's six principal rivers, has its source on the southerly side of the Hill of Stake in the heart of the Clyde Muirshiel Regional Park. About a mile and a half south of this starting point the untested stream tumbles over the Spout of Garnock, the highest waterfall in Ayrshire, once thought to be the river's origin.