Hidden among sand dunes and far away from the much more popular beaches is a really stunning lagoon. This lagoon hidden by the dunes had beautiful sandy shores and a small coral reef within it with only a small opening out to the wider ocean. Tropical fish swim without care among the reef as bright sunlight fill the clear ocean water with light. There is no sign of human activity in this place and that is by design.
At the center of this lagoon is what appears to be a small sink hole in which the ocean shows how deep it really is. For anyone who dares to swim near it they would think it was nothing special.
Only thing is that it is a door between the human world and a parallel world, a world of mermaids and merman.
That door however is guarded and anyone who comes near it will encounter the guardian of that door, and they will soon learn that being born human doesn’t mean they will forever be human for that guardian will not kill them but drag them down into that hole and transform them into a new mermaid or merman depending on the needs of the community they serve doesn't matter what gender the human was at first.
This had happened for countless years, people disappearing near to be seen again. As such locals tend to stay away but tourists and some less wise locals still unknowingly risk it to experience the beauty of the sea not knowing that they may never leave.