As part of a shore excursion we visited this old Castle Urquhart. Initially it took us a while to get our tickets because the line was pretty large. You will need to be fit for the visit here, there is a lot of walking up and down steps.
Very interesting though and it has great views over Loch Ness. We hoped to spot the infamous nessie but the weather was a raining and overcast. Still an interesting runied castle with lots to see and a good visitor centre.