Assos Castle or Assos Fortress was constructed in the late-16th century during the Venetian rule. Assos Castle remains till present in relatively good condition. It is an original architectural example of the fortification of Venetians who wanted to found a strong, permanently inhabited castle town. The Castle is built on the peninsula of Assos at a strategic location. The domed gate at the entrance of the castle,which is preserved in good condition till today, is also impressive.