You have to go to the big octagon-like door, hop over the elevators, and walk to the right, and jump down, and an exit will be somewhere down there.
go to the nearest fire exit andfind out the secret code(:
its in the museum on mainstreet of steamworks island :)
It's Steamworks Island #14th Island
(The solution is at the related question "How do you beat Steamworks Island")
the crab on steamworks island is next to the living quarters
This was a glitch in poptropica that they forgot to make a way for you to get out. If you have haunted house island or something like that, just go there and exit to go back to steamworks, where it will take you back to Main St.
You go to Steamworks and head to the museum and there is the Deogen
steamworks island
There is a video walkthrough at the related link below. There are written WikiAnswers solutions at the related questions, as there are for all Poptropica islands. (How do you beat Steamworks Island) (What is the walkthrough for Steamworks Island)
Exit right, come out by the windmill, and go right to reach the door to the elevator room. In the elevator room, go to the far right and jump down the shaft, and you will be at the exit. If you somehow end up on the bottom level, use the tree lift (left) to go to the second level, then jump hard to the right to reach the door. You can also use the Haunted House card to leave almost anywhere: enter then exit to the island map. If there is a new island, there may be a link to it on the Home page that you can use to leave Steamworks.
Steamworks island
how to do the bridge terminal on poptropica's steamworks island