What a lovely idea for a thread ... but where to begin.
I am going to choose Boscawen-un in Cornwall. Visited in 2010 with K, we went on our holiday to West Cornwall the year after he had been seriously ill. Neither of us could map read and he seemed happy to just go along with where ever I wanted to go. We didn't have a car, my map reading skills definitely left room for improvement, and we managed to get hopelessly lost more than once.
Our walk from St Buryun to the Boscawen-un stone circle was a complete success though. A beautiful, clear April day - I remember it vividly.