Cairn on the St. Lawrence. This is probably the only structure of the kind on the American continent. Cairn is a word of Celtic origin, used to denote the conical piles of stones frequently found upon the hills of Britain. These piles are supposed by some to have been erected as memorials of some local event, while others assign to them a sepulchral character. Some are supposed to be sacrificial, like the carnedd of the Welsh. They all have a smiliar appearance wherever found, being composed of loose stones piled in a conical form.