Ferries to Sifnos There are almost daily ferries to Sifnos from Piraeus, the largest port in Athens. The ferry trip from Athens to Sifnos takes from 4 to 8 hours, depending on the vessel and the route. This ferry also connects Sifnos with other islands of Cyclades, including Milos, Kimolos, Kythnos, Serifos, and others. Occasionally in high season, there are also ferries to Sifnos from Lavrion, the third-largest port of Athens, located on the southern side of Attica. > View ferry connections to Sifnos or Book online your ferry tickets to Sifnos!