The Subterranean Reception Room is a room underneath the Pillars of Shadow in the Cavern of the Gods in Endless Ocean 2. The entrance is behind the statue of Horus in the Altar of Horus, but, once unlocked, it is also accessible from the Altar of Isis.
The mural on the door to the Pillars of Light say that the "holy metal of magnesia" is the key to the underworld. After turning the ankh in the statue's hand, the statue moves, showing the players "the underworld" (the reception room).
This is the deepest room in the cavern, and, as its name suggests, this where, it is presumed, receptions for weddings, parties and other such things were held.
Within the Reception Room, you should find a school of Pineconefish, along with two or three Japanese Spider Crabs. In the zoom-mode "shine spots", there should be Cinderella Sea Slugs and a Marine Betta. Around the entrance in the Altar of Horus, there is a single Chambered Nautilus drifting leisurely about.
In the Altar of Horus entrance, there is a Large Container. The other treasures actually inside the Reception Room include:
- a Large Barrel
- an Ingot
- a Small Box
- a Large Crate
- the Eris Coin