So not true that it is best seen from above. Do go there and walk around and on top of it. It is a fantastic little broch with very well kept double walls, entrances, adjacent rooms and stairwells.
Dun Fiadhairt is an iron age broch with very well preserved double walls, guard cells and staircases. Well worth a quick stop if you are into what people lived in 2500 years ago. en.wikipedia.org/wiki/Dun_Fiadhairt