Abandoned Sawmill
Side quest
Skellige suggested level 24 
On the world map
From the journal
In a certain forest Geralt found himself looking at a clearly abandoned sawmill enveloped in thick undergrowth. He decided to investigate.
Curiosity once again dragged the witcher into trouble. Entering the sawmill provoked the leshen who had killed the woodcutters who had once worked there. Geralt had no choice but to fight the monster.