Pyrgos was one of the five castles of the island (the other being Oia, Skaros, Emporio, Akrotiri) and is the most well-preserved medieval settlement of Santorini. There was a single gateway to the castle, called Kasteloporta. About half a meter above it was a square building, called crenel or fonissa, equipped with a machicolation at the bottom, basically a floor opening through which boiling oil could be dropped on attackers trying to break into the castle. This building has not been preserved. A maze of galleries under the castle served to protect inhabitants and allow them to escape in case of an attack. The modern city was built outside and around the castle and was called Xeporto by the locals. Many of the old houses in Pyrgos and Santorini in general are cave-houses, i.e. narrow and long houses built into the rock.
Inside the castle of Pyrgos, on its west side, you can find Theotokaki or Koimisis tis Theotokou, one of the oldest churches in Santorini, which is believed to have been built in the 10th century with many additions having been made through the years. You should also visit the church of Eisodia Tis Theotokou, located at the highest point of the castle. It was built during 1660 - 1661 and is famous for the Epitaph procession on the evening of Good Friday. The procession goes through the entire village and thousands of tin lamps filled with petrol-soaked tow are lit, creating a sight you will never forget.

In 1995, it was declared a preserved monument by Unesco.
In the steep, medieval streets you can find wine bars and taverns, galleries and boutiques. The Santorini Museum of the Past houses exhibits from the island's traditional life, whereas the Icons and Ecclesiastical Artefacts Museum, housed in the former church of the Holy Trinity, features religious artefacts.
You can combine your visit to Pyrgos with a visit to the Monastery of Prophet Elias at the top of the mountain, 4 km south of the village. This monastery dates back to the 18th century and houses many religious artefacts, some of which datingback to the 15th century. The view from up there is breath taking as you can admire almost the entire island.