The fortress is in the mountainous village of Charakas to the north of Asterousia, and due to its fortified position, it controls the entire plain of Mesara.

The fortress is built on a rock, or haraki, as the locals call it. The rock is massive, 35m high, and 60m wide, with parts of a Venetian fortress and the church of the Transfiguration of the Saviour.

It is not clear when the castle was built, but archaeologists can distinguish two different building phases. The first belongs to the Byzantine period while the second that we see today dates to Venetian times.