Our top must see sights in Santorini island are:
Akrotiri is a Minoan Bronze Age settlement on the volcanic Greek island of Santorini which was destroyed in the theran eruption sometime in the 16th century BC and buried in volcanic ash, which preserved the remains of fine frescoes and many objects and artworks. The settlement has been suggested as a possible inspiration for Plato's story of Atlantis.
Prophet Elias, one of the oldest monastery of Santorini is situated on the summit of Mount Profitis Ilias that lies on the southeast edge of Santorini, 3 kilometers away from Pyrgos village, the highest settlement of the island. The monastery holds an impressive bell tower and is surrounded by four other churches and chapels.
Ia or Oia is a picturesque town beloved by artists and the tourists alike. Ia overlooks two sides of the sea, western with Ammoudi bay, eastern with Armeni bay; only western one of course faces the sunset. Being a destination for all those cruise ship passengers, the town so is very busy in the afternoons. It is far better to arrive in the early evening, allowing plenty of time to meander, shop and take photographs, then have a relaxing meal in a Caldera restaurant while watching one of the most beautiful sunsets. Be sure to occupy your seat in advance, though: western side becomes heavily crowded in the hour preceding sunset.
Ancient Thera is an antique city on a ridge of the steep, 36 m high Messavouno mountain on the Greek island of Santorini. It was named after the mythical ruler of the island, Theras, and was inhabited from the 9th century BC until 726 AD. Starting in 1895, Friedrich Hiller von Gaertringen systematically investigated the city until 1904. Later excavations by N. Zapheiropoulos between 1961 and 1982, under the auspices of the Archaeological Society of Athens, unearthed the city's necropolis in Sellada. Ancient Thera is today open to the public and can be reached on a winding road that starts at Kamari or several footpaths from both sides of the mountain.