The worst accommodation i can remember using , was staying at the Tarbet Hotel, at the top end of Loch Lomond.
Its owned by the Shearings coach company, and is a stunning building, which i believe has been recently refurbished. I MIGHT BE WRONG ON THIS ONE
My room overlooked the Inverary road, and at about five in the morning, the lumber lorries from the huge logging company the other end of the Rest and Be Thankful, used to accelerate past the window, you could hear the drivers change gear, and the first time i heard them, i could swear they were driving straight into the bedroom.
The bathroom was so dated, and the building so old and neglected, that the water from the poorly protected shower stray, went under the skirting board, because there was a slight gradient on the bathroom floor.
Goodness knows where the water was going, probably into specially placed buckets in a hidden room downstairs.
The nosh was excellent, but the during heavy rain, the indoor guest toilets were out of bounds as rainwater was pouring through the ceiling.
Ive never seen such a neglected establishment, that was charging good money to paying guests.