Santorini is the only Cycladic island with an active volcano, and the only one that has settlements built on the edge of the inner walls of the great crater formed by a volcanic eruption circa 1600 BC. Santorini and Thirasia form a ring around the Caldera, the bay created when the central part of ancient Strongyli sank to the seabed. During the ages, each eruption either destroyed the island or added new land to it. The one that took place in 1600 BC, during the economic and cultural pinnacle of the island, was named the “Minoan eruption”.  This dating placed the eruption between 1627 and 1600 BC, possibly in the years 1613-1614. Many other eruptions followed, and the lava flowing from the centre of the Caldera created Palia Kameni in 46 AD, Mikri (Small) Kameni in 1570 AD, and Nea Kameni in 1707 AD.The Santorini Caldera and the rest of the island are considered to be of extraordinary natural beauty.

The capital of the island is the centre of social activities, nightlife, shopping. Buildings that stood in Fira until the 1956 earthquake dated back to late 18th century. In the area of Fragomahalas, in the north side of Fira, you will admire the imposing houses of old Catholic families, Megaro Gyzi (17th century), now a cultural centre, the Catholic Cathedral, the Lazarist monastery. At Nomikos street, you will find the neoclassical building that houses Petros Nomikos conference centre. Just above that, is Goulas tower. Kato (Lower) Fira is a beautiful, quiet neighborhood built around the churches of Aghios Ioannis (Saint John) and Aghios Minas. A very popular spot of Fira is boudi (low wall), where visitors stop to admire the view. Opposite to boudi is the Cathedral of the Hypapante Sotira (Candlemas). The cobblestone street that leads to the center of the settlement is called Gold Street because of the jewelers that settled here many years ago. At Fira you will find many shops to buy clothes and accessories, jewells, art works, gifts. Also, you will visit the most important museums of Santorini and enjoy yourself at popular bars, clubs and restaurants that serve dishes of the local cuisine or gourmet menus. The town is lively all year long. Near the archaeological museum you will find the cable car that will take you to the Old port also called Gialos (tel.: +30 22860 22977). 

Oia is famous for its sunset and has become the most impressive settlement on the island. The hub of the village life is the main marble-paved pedestrian street, along which you will see some of the impressive captain’s houses. The Venetian district, built at the site of the old Goulas –a watchtower used during the rule of the Westerners– was ruined by the earthquakes. The meeting point for locals and foreigners alike is Platsani square. The castle of Aghios Nikolaos, as Oia was called back then, was named after the church of Saint Nicholas built from the 15th or 16th century. Later on, at the centre of the fortified village stood the Cathedral of Panagia Akathistos (Unseated Virgin Mary), or Platsani. A defensive hub is thought to have existed here since 1480, ruled by the Dargentas. In 1579, the Duchy of the Aegean was handed over to the Ottomans and remained under their rule for 250 years. In 1650, Columbo, the submarine volcano NE of Oia, erupted violently. Development in the area resumed in 1850. The effects of the 1956 quake were particularly severe, since parts of the ground collapsed into the sea. People started returning to Oia in the 1980s. With the contribution of the Greek National Tourism Organisation (GNTO) several buildings were restored. Today in Oia you will find gourmet restaurants, shops, galleries, hotels, care-bars.
Beneath the village there is Ammoudi, where you can eat at one of the several taverns by the seaside. The old port of Oia is Armeni: the ferries used to moor offshore here and people reached dry land on smaller boats, then went up to Oia on donkeys and mules.

The word Imerovigli comes from the words imera (day) and vigla (watchtower). Located at the tallest spot of the Caldera, it is considered by many as offering the best view. It is just 3 km. from Fira, and there is access either from the asphalt road, or following the cobblestone path from Fira and Firostefani. In Imerovigli it is worth walking along the Caldera and see the churches of Panagia Anastasis (Virgin Mary of the Resurrection) with the blue dome, Panagia Malteza (Presentation of the Virgin Mary) near the main square, Ioannis Chrysostomos (St John Chrysostom). Early in the morning, or in the evening take a walk towards Skaros and the ruins of the medieval castle, passing by the white church of Aghios Ioannis Katiforis (which means “Saint John going downhill”, probably due to the ground incline). At the impressive rock of Skaros once stood an inviolable castle, with the public and private buildings of the island’s capital hidden inside it. 
This lovely village that was characterized as a protected monument in 1995.  Known for its Venetian Casteli (castle) and the Good Friday custom involving thousands of lit tin cans, Pyrgos has recently developed into a significant tourist destination outside the Caldera.
The castle of Pyrgos was one of the five Castelia built in the 15th century by the Venetians in Santorini. Walking is a great way to explore both the newest part of the village and the Medieval hub. Cycladic houses blend harmoniously with the manors and the surviving old stores. From the top of the castle the view over the island is exceptional.