My personal favorite room in Edinburgh Castle is the highest St. Margaret Chapel, the oldest building in the castle, with three beautiful painted windows depicting how Margaret Queen became a saint ...... When you first see the true meaning of "The Stone of Destiny", don't be too surprised, yes, this is a big slate. The Scottish people say it is the travel pillow of Jacob in Genesis. It is a holy thing. The earliest record about it was that before the Scots, the Irish first used it as a rock, and later fell into the hands of the Scots.