Just behind and to the right of the Twilight Castle, you can find a path among the trees which leads to Danu’s Sacred Grove. Look for a carving of an apple on the side of a boulder and you’ll find the overgrown path which will take you to a little meadow within a grove of apple trees.
Within Fairy, it is simply a small grove within the forest. The grove surrounds a meadow with an empty cave. But if Danu chooses to bring you through the veil and into her realm, you will see an orchard that extends to eternity, surrounding a small cave which lovingly protects Danu’s altar.
The altar is a simple, flat-topped boulder with a basin carved into it. Water drips into this basin from a stalactite directly above. The altar itself is long and narrow, with steps beside it, so that a fairy might crawl onto the flat surface and gaze into the basin of water there. The water falls consistently in a dual drip pattern, eliciting a sound similar to a heartbeat.
This is where you can commune with Danu and if you’re very special, she may even give you one of her apples.