In truth, a former convent which was dissolved during the reign of King Otto (1832-1862), up until 2010, where it was in service again. It was built during the period of piracy that spread after the great Cretan war of 1645-1669 between Venice and Christian allies against the Ottomans.
It has the structure of a fortress: except for the northern side, which is naturally inaccessible, it is surrounded by high walls, with ramparts and embrasures. There were two towers on the southern part, of which only the one to the south-east survives, the south-western part having been reconstructed. The sole entrance on the west side was protected by such a well-made gate, (local Juniper wood was used, clad in sheets of iron), that according to the stories, a pirate raiding party, had to move cannons all the way up, in order to breach the gate. Of course, the present door is a replacement, but the original has been kept in storage.