Next to the village of Krya, 25km away from the town of Sitia, there is a hill with the church of St. George and the ruins of a Venetian castle, called Monte Forte or Apano Castelli (Upper Forth).

This position is strategic, because it controls the entire area. The fort has a maximum length of 120m, width of 80m and was built by the Venetians to secure their sovereignty against the local population. The name probably derives from the homonym fortresses in Italy.

It had two entrances from the south and the west side, which was the weakest part of the fortress. Inside the fort, the Venetians built the church of St. George, a two-aisled vaulted tank, bastions and several more buildings.

Monte Forte during the Agiostefanites Revolution (1211) was occupied by the rebels, but for a while. Similarly, during to the revolt of Skordilis - Melissinos (1128-1236) the fortress was reoccupied by the insurgents, but the Duke Gradonico managed to suppress the movement. Such was the fate of the Revolution of Alexis Kallergis in 1262.

The earthquake of 1303 completely destroyed the fort, but was rebuilt in the 14th century. Since then, it’s significance decreased and was, eventually, abandoned. During the Ottoman rule it was neither restored nor used, thus today there are a few ruins of the castle.