On the way up to Gudauri, you'll not miss this fairy tale fortress perched on the edge of the vast Zhinvali reservoir. Do take some time to explore. 

The complex consists of two churches and a watch tower, inside massive defensive walls. Prince Aragveli was the designer, and he used it as a stronghold base from which to attack neighboring mountain clans: a great place for some special photos and a stretch of the legs before continuing on your way.