The Arboretum is like the federal garden, plant, and nature center of the Oria Province.
It is the Garden symbol. The Garden represents paradise, innocence, unspoiled beauty, and fertility. The Hill (and smaller hills) are also a Garden symbol (they're also a green symbol).
The Arboretum and the Hill represent all of the mentioned things to Molly Reyes, Cassia, and Ky. Molly loves her job at the Arboretum and all nature, it is very special to her. The Hill is a haven for Cassia and Ky, somewhere private where they can be together and it isn't all developed.
