Psara Island, Greece.
Access is effectively only from Chios, apart from one weekly ferry which comes up from Lavrion (for Athens) on Mondays on it way to Lesbos (Sigri), Aghios Efstratios and Lemnos and returns down the same line on Wednesdays. The most regular connection is the F/B Nisos Thira (NEL Lines: T. 22710 43981, fax 41443) which leaves Psará every morning for Chios, except Tuesdays, and returns in the afternoon (4hrs).
During the summer months only, there is a caïque service from Limniá (Volissos) on the west coast of Chios which crosses to Psará on Saturdays and returns on Sundays (90mins.). Once on the island, transportation is very limited: there is no taxi or vehicle rental of any sort. If you do not have your own vehicle, it is only possible to explore the island by foot— and there is no roadside shade at any point.