Assos for many years was the capital of north Kefalonia, and since 1593 the domicile for the Venetian archon of the region. It was then that started the construction of the fortress of Assos. The completion of the building was done rapidly, something that proves its strategic importance.
The fortress lost this importance when Lefkada was in the hands of Venetians in 1684. But the Venetian archon maintained the administration of the region until 1797, when the Venetian possession stopped.
Nowadays, the derelicted fortress reminds nothing of its old splendor. The visitor can see the walls of 2000m and the residence of the Venetian intendant. Parts of the barracks are also saved as and the church of Saint Marcus. Really impressive is the dome-shaped entrance of the castle, saved in a pretty good condition.