This gem is the best kept secret on the island of Santorini. Almost always it is common to visit the island as part of the trip to the volcano, which usually takes you to the volcanic island of Nea Kameni and Palea Kameni and stops in Thirassia before ending at Oia to see the sunset.
Thirasia Island has only 9 square kilometers in size and has only one hundred and fifty inhabitants. Manolas village is the capital of Thirassia. Other smaller settlements are Korfos, Riva and Potamos. Manolas is composed of small and quaint houses painted in various colors. The main attractions of this island are the virgin beaches and unspoilt nature.
Facts to consider:
You can not go to Thirassia except in a tour.
There is no boat regular service (as such) towards Thirassia.
Staying two hours in the island is not enough.
How do we get to the island?
There is a boat in Ammoudi (below Oia port) which starts at noon and returns at 5 pm (Note: check these times in Ammoudi). It goes to the village of Riva, which usually is not even marked on any map. Here you can catch a bus to the main village of Manolas, or (if you are very animated) can begin to walk and experience the island as it was before the tourist boom.
Incidentally, Riva is the location of the church of St. Irene of which are believed to come from the name of Santorini. From Manolas, you can walk to the Monastery of the Assumption of the Virgin. Apart from this monastery, there are another twenty churches in Thirasia. Every year on 21th September, there’s a party in honor of the Virgin Mary.

