Journey

They exist, but they are hidden in the forest, in piles on the sea, and underground.

Thank you, I've already found them, built markets in both cities, and now there are no problems (there was enough money to buy wood to build a decent guild of mages, and now everything is much more fun).
Yes, I managed to defend the human city, as expected, although I had to sacrifice eight hunters (I have the replay). I also captured a stone mine and a dungeon - I released a demon, and now he's running errands for me.

Now I've descended into the next basement (where I found the wood) - it smells like demons, but I haven't reached it yet.