An impressive place, but it wouldn’t be my first choice because it is just wall to wall people. For a similar experience, where you can actually walk a few steps without smacking anyone aside, try Stirling.
We used Edinburgh as a hub. We traveled to lochness, Saint Andrew’s and one more place I cant remember. Overall Scotland was a great place to visit for 4 days!.
Castles on top of extinct volcano vents are the best castles.