It is located on Megalocharis Avenue and includes exhibits from all over Tinos and especially from the two largest sanctuaries – the Thesmoforio, dedicated to the Goddess Demeter, from the 7th century B.C., which was built on the slope of Xombourgo, and the Hellenistic temple of Poseidon and Amphitrite, in Kionia. One item of interest is the marble sundial that dates back to the end of the 2nd century and the beginning of the 1st century B.C. It is a complicated construction that shows the solar calendar, the equinoxes, and the solstices. It is unique in the world, a work by of Andronikos of Kyristos. (Open from 08:30 a.m. to 3:00 p.m., except for Mondays) Telephone number: +30 22830 22670