The Petrispines is a mountainous region forming the southern border of Stone Prefecture. It is composed of a forest of unnatural-looking stone spires thirty to fifty feet tall. Its closest real-world analogue might be Tsingy de Bemaraha in Madagascar.
Rainbow Dash travels through this region accompanied by Sweet and Reeds. While there, Rainbow discovers a group of bandits and disposes of them anonymously. Later, the Right Talon searches the area thoroughly while they are tracking down Rainbow's trail.