It is Santorini’s biggest village where you can find anything you need ranging from shops, cafés and restaurants. The medieval Kasteli is its most significant sight as it is an architectural masterpiece that is maintained in a very good state. It belongs to the category of fortified settlements and it was developed as a fortress surrounding the original core of the settlement. The outer (surrounding) houses were the ones that would shape the wall. While entering the castle you will come across the old temple of the Annunciation (Virgin Mary the Messiani). Walking out of Kasteli, you will be impressed by the dominant figure of Goulas (that is a tower-observatory built to protect the lords and inhabitants from any invasion).