Underworld

The Underworld is located under DOA Recording Studios in Los Angeles, California, although in the movie it is located behind the hollywood sign. It's where the souls of the dead go when they die. The Underworld is divided into various sections. The Judges of the Underworld decide where a soul should go based upon their life's accomplishments. Another name for the Underworld is Hades, likely due to the god in charge.

DOA Recording Studios
The entrance is managed by Charon, the reaper of souls. He takes them into an elevator and heads down, where they sail across the River Styx toward the opposite shore. On that shore, Cerberus stands guard. The souls must pass by Cerberus toward their afterlife.

Door of Orpheus
A lesser-known entrance, the Door of Orpheus, stands in Central Park, NY. Orpheus created it to retrieve the dead spirit of his wife, Eurydice. Music is required to open this door and Percy and Nico used it in The Last Olympian. It lets out behind the main gates, therefore being more direct to Hades' palace.

River Styx


Charon's ferry floats along this river on it's way to the main gate. In ancient history, Achilles used the river to become invincible. Since the river is so powerful, the person bathing in it has to pick one vunerable spot on their body to make sure you are anchored to their human life, or else they will dissolve into the river. Thus the saying "Achilles' Heel" came to be because he was defeated in his vulnerable spot, his heel.

Luke Castellan used the river to be able to host Kronos. His weakness was a small bit of skin just under his left arm.

Getting the idea from Nico di Angelo, Percy Jackson used the river to become invincible so he could defeat Kronos. His weakness was in the small of his back.

Judgment Pavilion
Once a spirit enters the Underworld, it enters the Pavilion, Where three spirits judge them and put them in a certain place, according to their actions during life. One of the three judges is known, King Minos. Annabeth mentions William Shakespeare and Thomas Jefferson being one of the judges.

The Fields of Punishment


The Fields of Punishment are fields of complete and brutal torture for souls of people who have done extreme wrongs in their lifetimes.

One of them being the mortal King Sisyphus who cheated death numerous times and tricked Persephone. Sisyphus was sentence to roll a boulder up a hill that would roll back down when it gets close to the top.

King Tantalus was also condemned here for offering his son up for food to the Gods. Upon his death, his punishment was stand in the middle of a lake under the branches of a fruit tree, but whenever he reached for the fruit, the branches would retreat from his grasp; and whenever he leaned down for a drink, the water would recede from him.

It has "miles of barbed wire separating the different torture areas." Some of the torture areas include being burned at the stake and running through cactus patches forever.

The Fields of Asphodel
Souls who don't wish to be judged go the Asphodel Fields. According to Grover, it is described as "standing in a wheat field in Kansas for eternity." Annabeth Chase stated that most people don't do either good or bad in their lifetimes, thus floating in the Asphodel Fields forever.

Elysium


Elysium is the place of paradise for heroes. Those who die a hero's death live in peace in Elysium. Percy states that is where he wants to end up and it is where the demigod and ex-Hunter, Bianca di Angelo is now. Charles Beckendorf, Silena Beauregard, Lee Fletcher, Ethan Nakamura, and Luke Castellan are also there.

According to Percy, the only part of Elysium that can be seen behind its locked gate are several houses from different time periods. The grass ripples in rainbow colors and it is possible for one standing outside the gate to hear laughter and smell barbecue cooking.

Isles of the Blest
The Isles of Blest is reserved for heroes who have chosen to be reborn three times, each time achieving Elysium. Not many people live in the Isles of the Blest, and not many will, as there are not a lot of people who do good in their life, according to Percy Jackson. Luke Castellan, was one of the few heroes who wished to go into the Isles of the Blest, when he sacrificed himself in order to destroy Kronos. Annabeth instead, tells him that he always put too much stress on himself.

It is described as a glittering blue lake with three small islands like a vacation resort in the Bahamas.

Tartarus
Tartarus is the darkest and deepest area of the Underworld. Tartarus is where the gods imprison their enemies, chiefly the Titans. Kronos is known for being held there. When a monster is slain, it is sent to Tartarus until they reform.

Tartarus is the lowest region of the world, as far below earth as earth is from heaven. Tartarus is described as a dank, gloomy pit, surrounded by a wall of bronze, and beyond that a three-fold layer of night.

The Forth Age
Before the battle when Kronos ruled, he kept the Hundred-Handed Ones and all the Cyclopes in Tartarus guarded by Kampe.

The Fifth Age
Tartarus is where Kronos, along with some other Titans, was imprisoned after the battle between the Gods and the Titans.

The River Lethe


The River Lethe is the River of Forgetfulness, and it is used on people who try for rebirth. It has pure black water and is seen in The Demigod Files.

Hades' Palace


Hades' palace is where he lives and operates his command over the Underworld. His gate is engraved with images of death and his throne is made of bones, with a flowery throne next to it for his wife, Persephone. Hades built it to resemble Olympus even though everything is black and bronze and on Olympus, everything is silver and white.