The Ochil Hills (; - from a Celtic word root, compare Old Welsh uchel meaning 'high') is a range of hills in Scotland north of the Forth valley bordered by the towns of Stirling, Alloa, Kinross, Auchterarder and Perth. The only major roads crossing the hills pass through Glen Devon/Glen Eagles and Glenfarg, the latter now largely replaced except for local traffic by the M90 Edinburgh-Perth motorway cutting through the eastern foothills. The hills are part of a Devonian lava extrusion whose appearance today is largely due to the Ochil Fault which results in the southern face of the hills forming an escarpment. The plateau is undulating with no prominent peak, the highest point being Ben Cleuch at 721 m The south-flowing burns have cut deep ravines including Dollar Glen, Silver Glen and Alva Glen, often only passable with the aid of wooden walkways.