The Old Navarino castle is a 13th-century fortress near Pylos, Greece. It is one of two castles guarding the strategic bay on which it sits; the other is the Ottoman-built New Navarino fortress. Locally, it is simply Palaiokastro or Paliokastro (, "old castle"). The castle sits atop an imposing rock formation on the northern edge of the bay, flanked by sheer cliffs; the naturally defensible site has probably been occupied since classical times. Although there are no physical barriers to access, the castle ruins have been declared "closed" because the structure is considered dangerous.