To your right. Note the glyph of Marquai in the middle. An over-grown glyph of Marquai. But it's still there. See here for an explanation and story.
See the flat eastern edge? Artificial. There used to be a bump there. It got cut away.
Arboros used to exist by the south-east of the Dark Forest. At one point it was threatened by bandits, the Night Lords, who were hidden in its centre.
If the forest can be thought to be under any sort of control, then it would be of the Red Lemon Empire, which has settlements both directly to the north and south of the forest, and is constructing a road that will pass straight through the centre of the forest to link these settlements together.
There are currently no settlements within the Dark Forest. This is due mostly to the settlements of Valour Hill on the northern border of the forest, and Castle Clover on the southern border, their totem poles effectively rendering most of the forest unsettlable.