In the shadow of Santorini (Thira), Thirasia can offer an alternative for those seeking authenticity, tranquility, and solitude. Along with Santorini, Thirasia was part of the island of Strongyle which separated after the great eruption of 1600 BC. Thirasia now forms part of the perimeter of the large caldera that formed in the years following the eruption. Its geomorphology closely resembles that of Santorini, but in contrast to the better known island, touristic development here has mainly focused on visitors who come as part of the daily tours of boats that depart from the port of Thira to visit the volcano on Nea Kameni and Palea Kameni. The reality for those who want to really know the island and love it is fortunately different.
The island is small (less than 10 square kilometers) and easy to roam around. It has a satisfactory road network with paved roads and passable dirt roads, but it is preferable to explore it on foot, at least in the places cars don’t go.
The capital of the island is Manolas, which was built on the brow of the steep slope of the caldera (volcanic crater). Quiet and picturesque, it is an ideal destination for those seeking a brief escape from the tourist crowds of Santorini. Two hundred seventy steps connect it with its seaport, the picturesque harbor of Korfos. Interesting and picturesque settlements are Potamos (inhabited) and Agrilia (the oldest settlement on the island, no longer inhabited). The main port of the island is Riva, in the village of Agia Irini in the north.
The island is of great archaeological interest, as much as Santorini, but since none of the excavations are accessible to the general public the interest is restricted to and historians. Some of the most notable of the visible findings that have survived are at the little Church of Christ (located approximately 1,200 meters south of Agrilia). At the northern end of the wall surrounding the church, part of a circular Hellenistic/Classical era tower has survived.
Thirasia has a few "wild" volcanic beaches with black stones and pebbles. Most noteworthy are the two beaches in the village of Agia Irini (Riva), the first at the port and the second farther south of the village, and those in the western part of the island. There is also one more in the north, the beach of Agios Nikolaos, which is inaccessible by land, beneath the steep slopes of the caldera.