First you have to get a mission from Zeus. Then keep going right until you get to Hades temple. Then to the right of it is a shooting block. Go on the block and ride to the top. At the top go right and you will see Poseidon's kingdom. Go in and put the sea star on the offering altar.
With Aphrodite's magic mirror.
Dive below
Poseidon is found on Mythology Island, which is a Poptropica island.
If you are talking about Mythology Island, there is no such thing there. Mythology Island only has three 'kingdoms': Hades, Poseidon, and Zeus.
Poseidon's hair color is blue.
Once Hercules helps you, use Aphrodite's mirror to go to Posidon's realm. Hercules will smash the rocks guarding Posidon's realm.
on the Poseidon statue
it is on Poseidon's statue in the museum
its on his palace/temple.
i think he is blue
in museum
it is on the Poseidon statue at the museum of the gods.