Redrobes-- I, too, was thinking of mixing a lighthouse on a peninsula with a pirate cavern underneath. BUT you posted your general idea first, so I don't want to take it and be accused of "copying". While my back story is drastically different, the fact that it contains a lighthouse and a cavern makes me leery of pursuing it. Additionally, I was going to do a "side-view" showing the elevations of the various caves.

If you do NOT want me to pursue these elements in my map, please say so, and I can change the concept. If you do not mind, please tell me that as well. I'm going to hold off moving forward until I hear from you.