38°16′03″N 21°56′20″E / 38.2675°N 21.9389°E
The Salmeniko Castle (Greek: Κάστρο του Σαλμενίκου, Kastro tou Salmenikou) or Orgia or Oria Castle (Κάστρο Οργιάς/Ωριάς, cf. Kastro tis Orias) was a castle at the foot of Panachaiko mountain, in the modern municipality of Aigialeia, Achaea, Greece. In 1461 it was the last garrison of the Byzantine Empire, holding out until eight years after the fall of Constantinople in 1453.