To get to Kea (also called Tzia), you usually take a ferry from the port of Lavrio, near Athens.
From Athens to Lavrio Port
By car or taxi: about 45-60 minutes from central Athens or Athens Airport.
By bus: KTEL buses run from Athens to Lavrio regularly.
Ferry to Kea
Ferries depart daily from Lavrio Port to Kea (Korissia Port).
The trip takes about 1 hour to 1 hour 10 minutes.
Ticket prices usually start from around ?16-20.
Main ferry companies include Blue Star Ferries, Triton Ferries, Goutos Lines, and Karystia.