Observatory Hill

Observatory Hill was a hill located in Ponyville, Equestria. The hill was locally famous for being a spot to observe astronomical happenings, such as the Centennial Celebration or just to watch the stars.

IDW comics
The hill may have been the spot the Mane Six, and  rested after Nightmare Rarity had invaded Ponyville with her army of Nightmares.

Naming
The place was never given a name in canon. "Observatory Hill" was a named used in a fanfiction of the same name.