Thank you all for your castle thoughts. We returned from our cruise this past Saturday, and had a great time. As for castles, we saw several -- one that was mainly for defense (Portland Castle), one that was primarily a residence (Caerhay's Castle and Gardens, near Falmouth), and two that were some of each (Cardiff Castle and Edinburgh Castle). They were all so interesting yet quite different from each other.
We were also set to go to Castle of Mey (thank you, queenofcruzin), yet high winds prevented us from anchoring in Scrabster.
My narrative/review is nearly done... I'll let you all know when it's set.