If you are passing through Huntly I recommend a stop. The village lies along major bus and train routes between Inverness and Aberdeen, so the castle is readily accessible after about a 10 minute walk from the bus stop and 15/20 minutes from the train station.
Historic Scotland operates the site - so there is historical information about, as well as toilets and a gift shop. Historic scotland members/pass holders get in free.
This castle is different from others I've visited in Scotland (and I've seen a lot) because of the details of the masonry and architecture that remain, which make it quite interesting. As ruins go, the part of the castle that remains is quite complete and there are 4-5 floors to explore. Not the best views of the countryside or landscape as others I have visited, so that is not necessarily a reason to go. It seems like this is a quiet stop with just a handful of visitors coming through at a time so it is very peaceful. The docents were very friendly and helpful, and also pointed out some places to eat in town, which was helpful.
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