Mycenae ( Greek MykÄ `` nai or MykÄ `` nÄ `` ) , is an archaeological site in Greece . It is about 90 km south-west of Athens , in the north-eastern Peloponnese . Mycenae ( Greek MykÄ `` nai or MykÄ `` nÄ `` ) is an archaeological site in Greece , located about 90 km south-west of Athens , in the north-eastern Peloponnese .