Orkney is full of the evidence of master builders. Once stone is placed upon stone, then something is created which can last many, many generations. Assuming it is done right.
Here’s a load-bearing lintel. Not just one, but three, separated by lines of small flat stones. It’s perfectly reasonable to ask whether the supports might be over-engineered until you realise this is in Orkney; then putting three lintels over your door or window seems a perfectly reasonable thing to do.
Beautiful, isn’t it?