The castle of Rio (or Kastelli of Patras or Kastelli of Moria) is located in the coastal area of Rio in Achaea (Peloponnese). Today next to the castle is the Rio-Antirio Bridge, to its right and left is located the east and west pier of the ferries. The castle was built by Sultan Bayezid II in 1499 on the ruins of the ancient temple of Poseidon, in just three months. Together with the opposite castle of Antirrio and with the firepower they had, they controlled the sea passage. Today the castle can be visited by tourists and it is also used for cultural events.