Environmentally sensitive area

Large parts of the islands are wildlife/vegetation sanctuaries, as indicated by this little sign. The question to stay on the tracks makes sense of course, but is largely superfluous, since it can be quite dangerous to venture off the beaten track. Many parts are marshlands, and due to the dense vegetation, it is quite likely one would end up drowning, trapped by the vegetation in some type of deep puddle with no way to get out.