Mylopotamos Castle in Kythira was built by the Venetians in 1566. The carved lion of Saint Markos, a symbol of Venetian domination, still adorns the central gate of the castle. The lion holds a book with the inscription: PAX TIBI MARCE EVANGELISTA MEUS, MDLXV ('Peace to you Evangelist Marco, 1565'). Obviously there was an older settlement there, since at least the 14th century, that gradually was developed and after the destruction of other parts of the island in 1537, it became more impoortant and was rebuilt. The position controls the west coast of Kythira and the Ionian sea, but the primary usage of the fortification was rather the protection of the local population.
Narrow streets and semi-ruined two-storey houses mostly with flat roofs, travel the visitors back in time. The ground floor of the houses used to serve as warehouses while access to the upper floor was through an external stone staircase. Inside the castle there are the remains of nine single-aisle churches of the 16th-17th century decorated with Byzantine and post-Byzantine frescos.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.