The Trident Chamber
The Trident Pool is a hidden location in The Hidden Mako Island Cave. It can be opened by someone putting their hand in the trident hole it would then turn the circle into a pool entrance. As soon as a mermaid or merman runs into the entrance they will automaticly without a delay grow their tail. Not many mermaids have been in this pool. If a non merperson enters they will appear in whatever they are wearing. If you have the trident and put your hand in the trident shaped hole instead of opening the chamber you will fall into the moon pool. This is shown in Decision Time.