I am staying in Fira and will have 3 full days to explore the island (Tues-Thurs). I am happy I am centrally located in terms of the bus system, but have no idea on how big the island is. It seems of all the routes the longest is about 30 minutes. To ensure I see everything I want is it better to "split" the island north/south or maybe east/west? Knowing how far the villages are from each other will give me a better idea of how much I can do in a day. Also, I will not have a car while I'm there and use the bus a lot now in my city so am used to transportation like this.