Moon lake

On the Northern side of the vast expanse of grazing land, two large rock-faces collide on a sixty-five degree angle, and in the erosion it created lay a huge fresh-water lake. It's water is crystal clear and pure as the sky, but too deep to see the bottom.

All horses are free to come here at leisure and drink from the cool water, or escape from the gripping heat of Summer for a swim.
Please note that this is the only place where horses may breed, and add in your post somewhere that they have ducked off behind some boulders or something, please.