In the past I've really liked placing them by the side of a dirt/stone road, in a grove of cedar trees, with a few blue and white violets nearby. Also a second bell beside a river, more south, with some mushrooms and more flowers. I love the zen bell. Good luck! Take a picture of the finished product
In my old town I had the zen bell, it was by a pond next to town hall. I liked to pretend that was the bell Isabelle rang when it turned 6am in town and she woke everyone up. (even if the bells don't sound the same haha) I put some cedar trees and a few flowers near it along with a small river qr path going around it.