The room that is in the Hidden Lake is the Underwater room which that is the place that is under the Ice Pond.
It is in the room next to the Hidden Lake
The Hidden Lake is a room for both members and non-members. It was first opened in the Cave Expedition where you needed to have the Amethyst Pin pin to come in here. It re-opened on March 15, 2010, where you didn't need any items to get in.On the right side of the Hidden Lake, there is a door to the Underwater Room, which is open only to members. As of the Island Adventure Party 2010, there is a permanent entrance to the Hidden Lake from the Forest[1], making it not really "hidden" anymore.
You completely finish the puffle game and you get a key.
You go to the nighclub. go up to the games room ( i dont know the name of it) play one of the games im not sure which one. after you completed the game you will get the key to the door in the hidden lake
Behind the door lies a hidden room called the underwater room in club penguin. Many girl penguins like to play "mermaids" in this room. There is also a pin in here called "moss key'' pin.
The Secret of Hidden Lake was created in 2006.
Well the Club Penguin hard hats are in the room right before you go to the hidden lake!
hidden lake
The diadem was hidden in the Room of Requirement
he is so joking. maybe he said that because there is treasure there. the real answer is that behind the door is a secret room. there is also a free pin. it is the key that you earned as a pin. when you click on it. it is called the mossy key pin
you have to be a member to get the key......go to the mine and play puffle rescue with the black puffle.....on level 1 get the puffle and wait there....you will see a squid ..go on the bubbles it produces onto the island ..go through the door in the island.. you will find yourself in a room .then you will spot the key ..pick it up and go to the hidden lake and enter ... you will find the room
it is on the hidden lake in the lake down