Its exact origin is lost in the mists of time, but its first use was probably as a barrow, an artificial pre-Christian burial mound of which there are many examples found throughout Britain. Doomster Hill was sited beside what was a very shallow part of the River Clyde. This area was a natural crossing point for the river. It may have been used by the Romans and others to guard and tax any movement of people or goods crossing the river. It may also have served as a 'law-hill', a moot or a place of assembly where judgements and punishment were administered.