The Temple of Jupiter Optimus Maximus is the most sacred temple at Camp Jupiter. It is where the augur, Octavian, reads the will of the gods by reading the entrails (i.e. stuffing) of stuffed animals. It is on Temple Hill, near New Rome.
Percy is brought here by Hazel to meet the augur, Octavian, to decide if he can stay at Camp Jupiter or if they will kill him. Percy asks Octavian why there is no Oracle, whom the Greeks used to read prophecy. Octavian states that the Romans relied on the Sibylline Books to read the prophecy, that have been all but lost. He then mentions the Prophecy of Seven, and that every person who tries to understand the prophecy causes bad luck. Octavian then proceeds to take Percy's pillow-pet panda, cuts it open, and reads its stuffing. He then states that Percy is allowed to live and join the legion.
There is a marble floor that is etched with many mosaics and Latin inscriptions. The height of the gold ceiling is above 60 feet. The temple is open so that the wind can get in. In the center of the temple there is a marble altar and a statue of Jupiter holding the Master Bolt. Percy mentions that the actual Master Bolt does not look like the one in the temple.
- This is one of the two places where Imperial Gold can be made, by consecrating it in the temple. The other is the Capitoline Hill in Rome.
- Even though Percy lost his memory he remembers that the Master Bolt looks nothing like the statues replica.
- It is named after the original temple in Rome.
- It is the largest of the temples on Temple Hill, due to it repesenting the King of the Gods.
- "Jupiter Optimus Maximus" means: Jupiter, the best and the greatest.