One of several strangely eroded features on the slopes of the Lomond Hills, John Knox’s Pulpit is an outcrop of grey sandstone laid down as desert sand dunes in the late-Devonian age, 410-353 million years ago, when this part of the Earth lay close to the Equator. The rock face shows thin layers called pin stripes which are characteristic of sand deposited by wind in an arid environment. There was once a cave at the foot of the cliff which was reduced in size by a major rock fall in 2004. John Knox’s Pulpit is still in a hazardous condition and the pathway leading directly below it has been closed for public safety. Though the 16th-century church reformer John Knox (c.1513-72) is never known to have visited Glen Vale, the natural amphitheatre formed by this outcrop of sandstone was used as a secret meeting place by Presbyterian Covenanters who held conventicles or church services here in the late 17th century.