Thank you for your ideas and suggestions. The black masses are passable by aerials as they are just water. The black color somehow makes them look like barriers when they are actually not.
And as for the map concept, I put pretty much time finding a proper map name and description but couldn't really come up with anything good. That's why people keep asking what the map is about and I agree with everyone. Even I think they suck.
What I was thinking is that the volcano is currently in an inert state. There had been eruptions, but that was very very long time ago. Like I said, I should have explained that in the map description but yeahh... as you see. I failed.
I will update it with a new name and description.