I visited Carnac primarily to see the stones and this hotel is a great location and easy walking distance to the site. I also walked to Le plage from here, there is also a bus just outside the door.
The rooms were very spacious, clean and the beds gave a perfect nights sleep. Yes it is an old hotel and some things are a little out-dated and in need of revamping BUT it is great value, the evening meal SUPERB and the staff very friendly and helpful.
There is free wifi but no mini bar and breakfast is 9 euro... no hot food.
I would stay here again.