Edinburgh Castle was especially important to visit as I have quite a bit of Bruce in my background. While that hunk of the family has never done much in the way of genealogies, we like to assume that we simply must be worthy of the Bruce coat of arms.
We missed it as it was a Sunday but they fire the cannons most days at 1300 hours. This acted as a communal timepiece much in the same way church bells might starting in 1861. The original plan had been the time ball on the top of the Nelson Monument but the rather perpetual fog, mist, and generally poor visibility inhibit the efficacy of a visual time marker.
J. K. Rowling wrote most of the Harry Potter books in and around Edinburgh. The release of the 6th book, Harry Potter and the Half-Blood Prince (where Ginny and Harry FINALLY get together, hem, hem) took place at Edinburgh Castle. I can't think of a better location. There is no doubt as to how you could be inspired to create Hogwarts, Diagon Alley and all the rest.