Siccar Point is now in the parish of Cockburnspath but was formerly in the parish of Old Cambus, from which the ancient parish church of St Helen's Chapel survives as a ruin about one kilometre to the west of the point. The church is built in a Romanesque style, in a mixture of Old Red Sandstone believed to have been quarried from the nearby Greenheugh Baycitation needed and of the greywacke rock also used in the drystane dyke forming the field boundaries. It is likely that the medieval village of Old Cambus was nearer to Siccar Point than the extant hamlet of Old Cambus.
To the south of the point twentieth century quarrying for greywacke to be used as roadstone left a hollow which is now occupied by a vegetable processing plant.
Hutton's Unconformity
The rugged point shows gently sloping beds of red sandstone above vertical beds of greywacke, forming a classic example of Hutton's Unconformity.
