Oh, that’s a nice article. Thank you for sharing! I did not know they made their sails probably from wool covered with tar. I definitely want to add this resource. A Tar Pit or Kiln will be not a problem. More how to manage this stuff in our limited flag system. :)
Since you are thinking about the tar pits, how about peat bogs, to gather peat for fuel?? I don’t know if was a northern thing to do. but I do know that peat, and cow paddies were often used as fuels. Yet nobody on Banished has made this happen. Maybe you can Tom.
I thought of peat or turf as a resource mined from the ground in small pits to build my new turf houses, but preferred a variant with it as a free/virtual building material. For fuel, we talked about peat some time ago on wob. I see problems with balancing because it should not displace firewood but leaving useless holes in the ground is not what players love. I also think that in reality it is not that easy. It contains rather less carbon and must be completely dry. However, in general it can work both in real and in game. :)