Thirasia: Santorini's Quiet Sister Island

One Volcano, Two Islands

Thirasia was joined to Thera until the Minoan eruption separated the two islands. That eruption is dated to about 1600 BC and is rated VEI 7. When the volcano blew itself apart, the old island broke into the crescent you see today: Thera on the east, Thirasia and the small uninhabited islet of Aspronisi on the west. Aspronisi is 650 m long and 200 m wide, partly made of white pumice, and it is a nesting ground for some migratory birds.

Thirasia covers 9.299 km2 (3.590 sq mi), which makes it the second-largest island in the group after Thera. National Geographic gives its shape as 5.5 miles long and 1.5 miles wide.

A Small, Steady Population

Thirasia had 249 inhabitants at the 2021 census. The count has moved around for decades: 233 in 1991, 268 in 2001, 319 in 2011 and 249 in 2021. National Geographic gives 168 permanent inhabitants, which differs from the census figure. Ferryhopper says the island has about 300 residents, with ATMs, a medical clinic, a grocery store and 7 tavernas.

The 2021 census lists the villages as Manolas 140, Potamos 74, Agia Eirini 28, Agrilia 5 and Ormos Korfou 2. Manolas is the main village. The island counts 24 churches according to National Geographic, and the Santa Irini church built in 1867 there gave Santorini its name.

Earthquakes Shaped the Island

A 7.8 magnitude earthquake on 9 July 1956 caused heavy damage across Santorini. National Geographic says it devastated the Agrilia settlement on Thirasia, which is today a semi-abandoned village with a Virgin Mary church. Across the strait, 35% of the houses on Santorini collapsed and 45% suffered damage in the same quake, which killed 53 people and injured another 100.

Boats and Ferries Compared

The table below gathers the routes the sources describe, where each one leaves from, where it lands and what to watch for. The sources give no fares beyond the Wikivoyage figure of EUR 10 or more per journey, and schedules change by season, so confirm times locally before you plan a day around a single departure.

Which Route Suits You

If you are staying in Oia, the caiques from Ammoudi are the shortest hop. Ammoudi Bay lies below Oia and is reached by about 300 steps down from the town, or by a narrow road. The bay itself is covered in more detail on the Ammoudi Bay page.

If you are staying in Fira or the south, the 25-minute ferry from Athinios Port at 3:30 p.m. daily except Sundays is the practical choice, and Riva is Thirasia's main port, on the north coast. Athinios is Santorini's main ferry port, and buses to Fira take about 20 minutes and cost roughly €2 to €3. Ferryhopper says a bus on Thirasia itself connects Riva, Manolas and Potamos, which saves you the climb if you are not up for the steps.

Korfos and the 270 Steps

Korfos on Thirasia is a narrow strip of black volcanic stone and pebbles with fishermen's houses and tavernas. Ormos Korfou had 2 residents at the 2021 census, so think jetty and beach rather than town. A 270-step stone path links Korfos beach to Manolas village above, and the climb is the main physical event of the day. Ferryhopper also notes you can reach Korfos by boat, skipping the stairs.

Thirasia's two beaches are Agia Irini with black sand and Korfos with pebbles and volcanic rock.

Manolas, the Main Village

Manolas sits on the caldera rim with 140 residents at the 2021 census. National Geographic describes steep stone steps, whitewashed lanes and cave houses, and the village faces the whole Santorini caldera from the quiet side. From Manolas you look back at Oia, and the cliff line from the quiet side.

Near Manolas there is a small market and bakery according to Santorini View. Santorini View also says the island has no dedicated medical center, which differs from Ferryhopper's mention of a clinic, so carry what you might need with you.

Potamos, Agrilia and the Inland Sites

Potamos has traditional cave houses and counted 74 residents in 2021. Agrilia, with 5 residents, is described as a semi-abandoned village with a Virgin Mary church, devastated by the 1956 quake. Agia Eirini had 28 residents, and Ferryhopper names Riva, also called Agia Irini, as the main port on the north coast.

For walking, Ferryhopper lists a hiking route from Manolas to the Profitis Ilias church and Kera village. National Geographic points to the Monastery of Kimisisis with a cobalt blue dome at Trypiti Cape. For wine, the Mikra Thira winery runs the only vineyard on Thirasia and offers 90-minute tours with tastings, though tour prices and booking details are not stated.

Three Cruises That Go There

The pick for the island itself is the Caldera Yachting Thirassia, a semi-private catamaran for up to 16 guests that lists Thirassia as its first stop, before the volcano hot springs, White Beach, Red Beach and Black Mountain. It costs $229.06 per person, runs 5 hours, and includes a seafood lunch with salads and dessert plus an open bar with local white wine, beer and soft beverages. Hotel pickup is included and there is free cancellation up to 24 hours before departure.

The Santorini Star Catamaran is a small-group catamaran capped at 18 passengers for $111 per person. Its 5-hour route stops at Red Beach, the hot springs, Thirassia and Indian Rock, with finger food, a meal of seafood, meat and vegetarian options and an open bar that pours a glass of Prosecco. It leaves from the old marina at Vlychada.

The Yachting Cruises Sunset Dinner sails daily at 3:00 PM from Vlychada for $125.98 per person, for up to 20 guests. Thirassia is on the stop list with Red Beach, White Beach, the Venetian Akrotiri Lighthouse and the hot springs, and the ticket includes a Greek dinner, soda, bottled water and alcoholic beverages.

What a Thirassia Stop Is and Is Not

Catamarans cannot moor directly on the beaches anywhere on this route, so they anchor as close as possible and guests swim from the boat. On these cruises the Thirassia stop is a swim stop off the coast, not a landing at Korfos or Riva. Do not expect the 270-step climb or a visit to Manolas on a catamaran stop.

If you want your feet on the island, take the caique from Ammoudi or the Athinios ferry, then book a cruise another day. The full route and every stop is laid out on the page covering the stops on the route, and if you are torn between departure times, the page on a Santorini sunset cruise explains how the evening runs.