The Altar of Nephthys is a room in the Cavern of the Gods in Endless Ocean 2.

As its name suggests, this room is meant for worshipping the Egyptian god Nephthys, the goddess of lamentation, the sister of Isis and the guardian of Osiris, who also have their own altars in the cavern.Like every other altar worshipping an Egyptian god or goddess in the cavern, it is simply a room with a statue of the god or goddess the worshippers are there to pay tribute to.

It is first encountered in Endless Ocean 2 at the end of the main plot. After losing Hayako in the cavern, GG looks for Hayako while the player and Oceane swim to the Altar of Nephthys and play the Dragon Flute and hear the song of dragons before losing GG.