Keros Island, Greece.
By boat: for such small islands as these, the ferry-services are frequent. The main-stay of communications is the F/B Express Skopelitis (with capacity for a small number of vehicles), which leaves Katapola on Amorgos daily in the early morning, and plies the route to Naxos, via Koufonisi, Schinousa, and Herakleia, returning (3pm) down the same line from Naxos: three days a week the route also includes Donousa. Blue Star Ferries follows the same route three times weekly, con tinuing directly to Piraeus from Naxos. Donousa is less well-connected, with one weekly service to Piraeus (7 hrs: currently Mondays) with Blue Star Ferries, and three weekly connections to Naxos and Amorgos (Mon, Wed, Fri) with the Express Skopelitis.
Keros Travel Guide