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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.
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.
Hercules will help you remove the rocks blocking the throne rooms of Hades and Poseidon. But only once Zeus has the 5 sacred items will Hercules will agree to help you. When you have all the items, take them back to the Tree of Immortality.
When you finish going to Hades' throne room ,use your mirror from Aphrodite and click Hades' symbol.Then,click on Hercules.Hercules will crunch the rock blocking Poseidon's throne room.Then you can go into his throne room.
get the five sacred items, give them to Zeus, go to Hercules, and use the mirror to get there.
Hercules is not going to help you during the hunt for the Five Sacred Items. It is only after Zeus has taken them from you that he agrees. His contribution is to move the large rocks blocking you from the Hades and Poseidon throne rooms. He also smashes the lock on the Mount Olympus gate. When he is turned to stone by Medusa, that is where he stays when you finish the island. He may return for another adventure on Poptropica.
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herculese opens it after Zeus takes all your items
Find all five items, talk to Athena, then Hercules and then use the mirror togo to Hade's door.
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.)
Hercules is not going to help you during the hunt for the Five Sacred Items. It is only after Zeus has taken them from you that he agrees. His contribution is to move the large rocks blocking you from the Hades and Poseidon throne rooms. He also smashes the lock on the Mount Olympus gate.