From Bulbapedia, the community-driven Pokémon encyclopedia.
(Japanese: ほしふりの丘 Starshower Hill) is an anime-exclusive location in the Alola region, found on Ula'ula Island that appeared in SM079. It is located atop Mount Hokulani near the Hokulani Observatory.
Starshower Hill is known for the large amount of Minior that fall down there from space. The Minior land on the surface in their Meteor Form, but eventually their shell cracks open. Once the Minior have lost their shell, they vanish into dust. Sophocles visited Starshower Hill when he was young and made friends with a Minior, only to lose it when it lost it shell.
Years later, Ash and his classmates visited Hokulani Observatory with Professor Kukui as part of a school trip and watched the Minior fall down from the sky at Starshower Hill. Just like Sophocles did before, Ash's Poipole befriended a Minior, only to lose its friend when it turned into dust. After all the Minior were gone, Ash and his friends spotted a Rayquaza in the sky.
Pokémon seen at Starshower Hill