Hades' Palace

Hades' Palace is located in the Underworld and is the home of Hades, the god of the Underworld and his wife, Persephone, the goddess of springtime, flowers, and young life.

Description
The palace is modeled after Mount Olympus, as Hades is not welcome there for the other parts of the year, unless it is the Winter Solstice. It is black and bronze, while everything in Olympus is silver and white. A person can only reach the palace if Hades wishes them to. If he doesn't, the person will just keep walking for eternity without ever reaching it. In front of the palace is Persephone's Garden, which has been said to be one of the most beautiful gardens on Earth.

Known Rooms

 * The Throne Room – Hades sits upon a black onyx throne made of skulls, surrounded by dead U.S. revolutionary soldiers, British Redcoats, Greek Warriors, Roman Legionnaires, Modern U.S. soldiers, and Confederate soldiers (as security). He is also surrounded by hellhounds.
 * The Dungeon – Hades imprisons Percy Jackson here in The Last Olympian. The cells do not have any doors or windows and apparently no source of oxygen for living prisoners.
 * Nico's room – Hades orders Nico di Angelo to go to his room in The Last Olympian. It is only mentioned.
 * Persephone's Chambers – In the Sword of Hades, Hades threatens to lock Persephone in her chambers for disobeying him. She continued to have a sword made after Hades did not approve its creation.

The Lightning Thief
Percy, Annabeth Chase, and Grover Underwood visit to diplomatically ask Hades to give them Zeus' stolen Master Bolt. Hades is found sitting on his throne, facing away from the three heroes. They later make a hasty retreat using Poseidon's Pearls.

The Sword of Hades
Thalia Grace, Nico, and Percy are summoned to the palace by Persephone to retrieve Hades's Sword which was stolen by Ethan Nakamura. They are first summoned to Persephone's Garden then they are brought to a veranda overlooking the garden. After retrieving the sword, the group return to the palace to return the sword to Hades and Persephone. Percy and Nico talk on a balcony overlooking the Fields of Asphodel where Nico reminds Percy of his idea to make Percy immortal by bathing in the River Styx. Percy promises to think about it. Thalia and Percy say goodbye to Nico, whom chooses to remain in the Underworld to advise Hades in the coming Titan War.

The Last Olympian
When Percy goes to the Underworld with Nico to bathe in the River Styx, Nico reveals that he had tricked Percy to get information from Hades about Nico's past and his mother. He hands Percy over to the Furies, who take Percy to Hades palace. Hades talks with him for awhile then sends him to the dungeon, a place below the palace. The dungeon is guarded by ghostly warriors and other dead. Percy is held there for a short time until Nico shows up to rescue him. They escape from the dungeon, and make their way to the River Styx so that Percy can bathe in it and gain the Curse of Achilles.

Trivia

 * Percy visited the palace three times in the series and escaped alive: The Lightning Thief, The Demigod Files, and The Last Olympian.
 * Demeter highly disapproves of Persephone living there with Hades because she claims there is not enough cereal for what she considers a proper breakfast.
 * The palace is run by skeleton servants.