Bourtzi is a small island with an area of 30,000 sq.m. at the entrance of the port of the island of Poros.
There was a castle on the island since the Byzantine period. It was used then as a base of operations against the Saracen pirates.
The castle remains that we see today are from the fort that was built there in the 19th century by the Bavarian Philellene Carl Wilhelm von Heideck (1788-1861) who had served as chairman of the Funds Raiser Committee of the new Greek State.
