Poseidon's Cabin is low, long, and solid, with all the windows facing the sea. The outer walls are rough gray stone with pieces of seashell and coral and look like the bottom of the ocean floor. On the inside it has six empty bunk beds, with silken pearl gray sheets and sea blue blankets and the walls glowed like abalone. There is a fountain used for Iris Messaging in the corner by the window facing the sea. In one corner of the room, there is a space for each cabin member to put a pet.
The place is rather messy, seeing as it is mainly occupied by boys.