Um, actually, yes. Ever taken the underground to Manhattan in NY city? Or the chunnel beneath the English channel? In fact, nearly any island with a high population density and close proximity to a major metropolitan area has underground access.
Go to counterfiet island.
go to the bottom and fight the monster
To get the underground paper on Counterfeit Island in Poptropica, you need to go into the underground tunnels underneath the museum area. Look for a grate on the ground that you can pry open with the crowbar item. Once you open the grate, go down into the tunnels and follow the path to find the underground paper.
go in the underground tour
Go through the underground tunnels.
the picture on counterfeit island is a picture for when you go underground and you go on top of the ladder u fix the dragon the way it is on the picture
you go in the underground cave but first you need to get the tickets.
go underground and there is a gate use it over there
it is in the underground at counterfeit
There are no switches, and no underground locations on Spy Island.
Go to the right from Main Street. (see related question)
First, you go to taxi in HENESYS and then go to the beginner's area and there should be a black taxi. Go there and there you go.