It is hard to tell if the placement of these tree-lines are natural... insofar as anything is 'natural' in the Tir. They effectively screen off sections of the valley allowing whoever lives here not only areas to graze in privacy but also the ability to watch the main meadows without being observed.
You descend down into the valley, the air growing cooler as you descend. At the far end you can make out a few traces of mist swirling beneath the trees.
There is a fleeting flash of white beneath a copse of the dark trees not too far away, pale against the dark green foliage.
Curious you stride into the shade to locate whatever creature it was....
Nothing. Not so much as a mark on the ground where you are certain it stood. "You won't find her. She's gone now." A soft voice murmers in your ear.
Startled you spin on your heel, watching you mildly through silky white lashes is an unicorn mare. Her dandylion-tuft mane floats lightly in an aura around her head. She must have slipped around behind you while you were intent on your search.
As if reading your thoughts she shakes her head. "Twas not me you just saw, nor any of my kind. It was Amya Tigerblood, one of the Mahnon Pah'llocks foundlings who chose to stay in the Tir, she resides in the forest."
The mare tosses her head. "I am Pah'ki, daughter of Alidus and Nimue of the realm of Lady Brooklyn. And this is my son, Tsur'ghi."
There is a soft whuff of breath behind you and, looking over your shoulder you note the presence of another.
Like his Dam Tsur'ghi too glows like a pearl in the moonlight, his large eyes dark and gentle.
"My sire, Jewel lives in the realms of Takana"
His voice rumbles from deep in his throat, like a thunderstorm on the horizon.
"Though he visits when he can. Sitha also shares our valley though he prefers to graze alone more often than not... You can probably find him further to the North."
Politely the two answer many of your questions about their species and this part of the Tir but when you ask about the Pah'llock Amya the two unicorns look at one another enigmatically. Pah'ki shakes her head gently and melts away back into the forest soundlessly. When you turn back to confront Tsur'ghi with the question you find he too has gone. There is no sound but the soft russss of the wind through the fir trees.
You could try finding Sitha, venture into the forest here or return to the main meadows.