The Old Surgery is in Kinlochbervie, up in the far northwest of Scotland. It's a detached house. It used to be the village doctor's surgery. I remember going there as a kid.
It sleeps four. Two bedrooms, one double and one twin, and a shower room. It's got a 4 Star rating. It's comfortable and clean. The layout is open plan downstairs. The back garden is enclosed, which is good if you have dogs.
You can see the sea from the front. It looks down over Loch Inchard and the fishing harbour. It's a working port, so you'll see the boats coming and going. It's interesting to watch.
You're right on the NC500 route. Durness is about half an hour's drive. Kylesku and Lochinver aren't too far either. The main thing is the beaches. Oldshoremore Beach is just over two miles away. It's beautiful. Polin and Sheigra beaches are nearby too. You can walk from Blairmore to Sandwood Bay, which is famous. They're all looked after by the John Muir Trust.
Facilities: there's parking, wifi, a washing machine, dishwasher, and TV. Bedding and towels are included. The entrance is wheelchair accessible. It's fine for Christmas stays. You can bring two dogs.
Useful links for planning: John Muir Trust and VisitScotland Highlands.