On the 4-player map, there are 4 Black Mountain spaces where you place Black Mountains. So far, so good,
But then there is a black lava Skull tile and another black lava tile. Are these Black Mountain spaces also? I assume so.
Lastly, there are two Black Mountain spaces with monsters already in them. Do these get Black Mountain counters?
All black mountain spaces - including ones that have lava on them as artwork. If it has a monster symbol, it will also get the monster placed there as well.