You cannot get into the throne rooms (except accidentally) while you are recovering the sacred items. Take them back to the Tree of Immortality.
Once Zeus has the items, Hercules will help you, providing you have the Touchscreen Mirror from the test by Aphrodite. He will let you enter the throne rooms and also open the gate to Mount Olympus.
You get it in Hades palace for cleaning graffiti for a worker in the throne room.
In Poptropica's Mythology Island, Hades' throne room is located in the Underworld, which is accessed through the entrance in the Tree of Immortality. Once you navigate through the challenges in the Underworld, you will reach Hades' throne room where you can defeat him and complete the island quest.
Place it on the offering stand in Hades throne room.
After you collect all five sacred items, return to the Tree of Immortality. Zeus will take them. Then you can go to Hercules and talk to him. Use the Touchscreen Mirror to teleport to Hades throne room and Hercules will move the boulder.
You can only enter the throne room of Hades when you have Hercules with you. That cannot occur until after you have collected all five Sacred Items and had them stolen from you by Zeus. Then Hercules will get you in to see Hades, and also Poseidon.
The Temple of Hades is in the Grove of Temples. You will need the Pomegranates from the tree in the Garden of the Sphinx (far left of the island). Place them on the altar and go down into the abyss, and cross the River Styx to find Cerberus and the Hades Throne Room.
if your talking about Zeu's throne room, ask Heracules If ur talking about Posiden youhave to put a starfish on the palette. If you are talking about Hades, you have to put a pomengranete
Through his throne room to the far right of the island.
Hercules will not help you until you have collected the 5 sacred items and had them stolen by Zeus. You will need the Touchscreen Mirror from Aphrodite's test on the beach. Transport yourself with Hercules to the Hades door and he will roll back the big rock. He will do the same for the rock blocking Poseidon's throne room.
Once Zeus has taken the 5 sacred items, Hercules will agree to help you, and will move the rocks blocking the way to Hades and to Poseidon. (You will need the Touchscreen Mirror from Aphrodite in Poseidon's realm.)
You have to get Hercules to do it (I forgot how to get him to help, sorry!)
His throne room is in the Temple to Poseidon, at the bottom of the lake. But you can only reach it when you have Hercules to move the boulder blocking the entrance. If you accidentally enter the Throne Room by slipping past the rock, you may not be able to get out again unless you have the Transporter Mirror.