Delphi, in the place fitted between space and time where she receives her visions of near and far futures.
Princess Delphi first started having prophetic visions as she aged into a teenager. At first she was unable to control when or what futures she could see, her sleeping mind at the mercy of her future vision. Celestia and Discord were concerned as to why their middle child was suddenly so exhausted during the day and stressed, but Del is very good at avoiding questions. Luna stepped in though, searching for her niece in the dream realm to find some clues — only to find that Delphi wasn't exactly there. She was dreaming, yes, but she was not having ordinary dreams.
After a short while, Delphi cracked. She talked through what she kept seeing with her aunt and parents, and at the suggestion of Twilight, left Canterlot to study magic and meditation with Zecora. Nowadays she resides in the Everfree forest with her mentor, and provides answers to anyone who seeks her out. She visits her family every couple months and more often visits her Auntie Fluttershy in Ponyville.