Skulls are supposed to represent very diverse "dangerous places" - either dangerous for those who visit them (dungeons, abandoned temples etc) or dangerous as sources of threat to surrounding lands (fortresses, portals etc). I will consider adding an option to hide them. Any ideas for an alternative symbol to denote such places are welcome!
I think the skull is a good icon to represent that. Having the ability to hide the skull or change the icon to one of the existing ones would be cool.
As a stretch, allowing for custom icons would let people add whatever they want. Would be really cool to change all the icons, like the trees and mountains. I would think it would only involve exposing the icon being used and allowing the user to change it, leaving the generation logic untouched.
For me I’d be happy with the Skull being replaced by a Dungeon, Temple, Fortress or Ruin if that’s what it is meant to represent.
I like to use this tool to quickly generate a world map, and for me the Skull is too “pirate-y”. I’d love it if the maps had the options for just castles and towns and other sites like that.