Grimble, MacKinnon and Celeste Ray are all worthwhile reading. None of them are difficult, but are all interesting. I have corresponded with Ray before and find her very intersted in learning more.

Another book similar to Ray's is "Cracker Culture: Celtic Ways in the Old South" by Grady McWhiney. He essentially ties descriptions of Ireland and Scotland to that of the Old South (US), while tying England to New England. While it sounds like bad history, it is actually well written, defended, and reasoned. It actually by a university press: University Alabama Press.

Amazon:
http://www.amazon.com/gp/product/081...lance&n=283155

I've also come across a few other "Clan history" books, but find MacKinnon and Grimble as the most useful. My copy of MacKinnon is my third. One lost on my trip in Scotland during 2000 and the other borrowed/donated by/to another. I have 2 copies of Grimble (purchased separately because differnt formating, I didn't realize was same book till started to actually read it).

Back to orginal post.

It is interesting how the island/penninsula was accessed in times of old. How did they climb it, is there some under/above water tunnel, flooded at high tide?

Good defensive locations are often reused by subsequent settlement, so a direct blood tie to the Iron Age settlement may be questionable. That said, people tend to not leave their ancestral home easily. (For example, just see the MacNeils and their fierce adherence to to the small, barely inhabitable island of Barra.)