If you mean the hatch thing on the roof in the middle you have to collect all 6 pieces of torn paper to form a picture of the dragon lock mechanism. Adjust the mechanism so it matches the picture and it will let you in.
You go to the city docks and enter it from there
First, you have to collect all 5 pieces of the dragon drawing. Then, rearrange the locks features to match the drawing.
You have to match the eight facial features of the paper dragon to the dragon on the top of the tunnel. It will take you to the supply room. - Good luck!!
You have to find all the pieces of the picture, so that you can open the secret entrance in the underground tunnel.
You don't. Later in the game, you will receive a key to open the door of the cottage.
First, you have to find all the pieces of paper around counterfeit island. When the pictures are assembled together, it will show a picture of a dragon. Make sure the dragon on the door is the same as the dragon in the picture.
During the Tour, you can recover the torn picture piece. At night, you use the pieces to open the lock and enter the museum from below.
The curator of the Museum Fantastique summons you to Early Poptropica and gives you a key, which fits the cottage door.
I forget but I think the lady in the museum gives the key to you...
To get the museum to let you in on Counterfeit Island, you have to go through the Underground Tunnel, then exit the tunnel, where it leads you to the City Docks. There will be a man waiting near the exit and he'll tell you to get a job at the museum, then meet him at night. You go to the museum and tell the guard you're there to apply for the job. He'll let you in the museum.
In the tunnel up a chain.... However to enter you first need to get a job. Be sure to colect pieces of paper to open the trap door.
The art museum on counterfeit island opens after you go to the guy at the dock.