We went to a winery and then to town, did a lot of damage at a jewely store, then walked, and took the donkeys down and returned to the ship, we were the last tender to get back to the ship, before a wind storm like I have never seen before, we were very late in leaving that evening, but Santorina is one of our favorite places in the world. I don't think you will need privite guide there, not a lot to see, just remembered there are some ruins there. I will be the big 60 this year , so my memory fails me most of the time. Anyway thats a good excuse.