The remains of a stone roundhouse (Broch) which it is believed to have been constructed around 200BC. Originally there would have been staircases between the outer and inner walls of this Broch. Note the very low/small entrance at the right side of the structure.
According to some internet sources the Broch was in use until the 1500's as a stronghold for a family. However that family were having a bit of a dispute with another family who allegedly smoked them out.
In my opinion and from a purely Landscape photography perspective this Broch is a better subject than its fairly close neighbours the Callanish Stones. To support my opinion for those who wish to see it there is a panorama image of the Landscape around the Broch on my Flickr Photostream.
Having said that I have made images of both sites . As always your thoughts, comments or suggestions are most welcome.