Hi Sylvie, After looking at the site, I would say its natural. I've spent years looking at megalithic sites in South/Central America and Europe, hoping that this was also a Canadian one but unfortunately it was not. The stone is of a very soft sandstone, the "blocks" do look carved but if you look underneath them you can see they are connected by a base of even softer sandstone. Sort of a small hoodoos. The native people of the area never cosidered the rocks as spirituly important, as I could find no information from any of the elders that I talked to. Sometimes, big rocks are just that, nature playing tricks on us.