Light tower on the banks of the Tay

Light tower on the banks of the Tay is a castle, fort or tower in Dundee City, Scotland. Perhaps it stood as a warning or invitation, its stone edges catching river light while people passed below. Maybe the tower watched for ships, thieves or strangers, and its keeper read the water like a book. Imagine a small fire moving along the bank at dusk, not for show but for life, marking the edge of the known world.