The shape of the castle of Koroni is probably square. It consists of two sets of walls, while the citadel is standing on its western part. It is worth mentioning that this point is the highest of the castle. The north and the south side of the castle are overlooking the sea. On the south side, there are sharp rocks - the rocks of Resalto, which end at a beach. The north side, which is the main entrance of the castle, leads to the houses of the town that are stretching up to its west side while its east side is facing to Livadia.
The main entrance is shaped in a large square construction, where the peak, at its lower part, is ending to a pointed arch. At the highest point, where there was the room of the guards of the gate, there is a curved arch.