Enchanted Forest

The Realm of the Unicorns is the home of the unicorns. It made it's first appearance in "The Last Mabelcorn", in which Mabel, Candy, Grenda, and Wendy went on a quest to obtain unicorn hair used to protect the Mystery Shack.

History
The Realm of the Unicorns was a place which Ford discovered during his research of the paranormal in Gravity Falls. During his research, Ford found out that the only way to access the realm is to "below [this] ancient chant droned only by the deepest voice druids of old", the chant opens the doors to the realm itself.

In "The Last Mabelcorn", Mabel, Candy, Grenda and Wendy go to the Enchanted Forest in order to find the unicorns so they can get a lock of unicorn hair for Ford. When they find the place, Grenda belows the ancient chant accessing the golden door to the Realm of the Unicorns.